The word microscope is a combine

Контрольная работа по английскому языку в 11 классе за 3 четверть. (вариант 1)

1. Read the text and complete it with the phrases (a-h). There is one phrase you don’t have to use.

a) surgeon operates  the instruments

b) by an electronic device

c) the building of surgical robots

d) because they can detect the change in acidity

e) becomes more difficult

f) on a special screen

g) the operation can be done faster

h) safe are these robots

Now there are robots that help surgeon perform operations. What can they do and is there anything to fear?

As surgical techniques become more advanced, keeping close control over everything that goes on during the operation (1)_________. The need for greater control and sensitivity has led to (2)_________. Keyhole surgery has s lot of benefit from their help. Specially adapted instruments on the ends of thin tubes are put through a small hole in the patient’s skin. The (3)_________ from outside the body using an instrument called a laparoscope, which has a camera on it. Thus doctors can watch the whole operation (4)_________.

The Laparobot or the robot laparascope gives the surgeon  greater control over the image on the screen, so (5)_________. The Laparobot is controlled (6)_________ worn by the surgeon. The position of the camera inside the patient follows the surgeon’s hands movements. But how (7)_________ ? Unlike industrial robots, these new surgical robots are designed to be extremely sensitive to the environment and respond quickly to any change. For instance,  they stop if they bump into an unexpected blood vessel.

2. Translate into English.

1. изумительный 2. захватывать 3. понимать 4. убедительный 5. тонуть (о людях) 6. выставлять 7. верный 8. роскошный 9. обладать 10. выпускать 11.искать 12. подходящий 13. подозревать 14. стоящий 15. придираться

Контрольная работа по английскому языку в 11 классе за 3 четверть. (вариант 2)

1. Read the text and complete it with the phrases (a-h). There is one phrase you don’t have to use.

a) safe are these robots

b) the operation can be done faster

c) becomes more difficult

d) on a special screen

e) the building of surgical robots

f) by an electronic device

g) because they can detect the change in acidity

h) surgeon operates  the instruments

Now there are robots that help surgeon perform operations. What can they do and is there anything to fear?

As surgical techniques become more advanced, keeping close control over everything that goes on during the operation (1)_________. The need for greater control and sensitivity has led to (2)_________. Keyhole surgery has s lot of benefit from their help. Specially adapted instruments on the ends of thin tubes are put through a small hole in the patient’s skin. The (3)_________ from outside the body using an instrument called a laparoscope, which has a camera on it. Thus doctors can watch the whole operation (4)_________.

The Laparobot or the robot laparascope gives the surgeon  greater control over the image on the screen, so (5)_________. The Laparobot is controlled (6)_________ worn by the surgeon. The position of the camera inside the patient follows the surgeon’s hands movements. But how (7)_________ ? Unlike industrial robots, these new surgical robots are designed to be extremely sensitive to the environment and respond quickly to any change. For instance,  they stop if they bump into an unexpected blood vessel.

2. Translate into English.

1. изумление 2. захватывающий 3. понятный 4. убеждать 5. тонуть (о неодушевленных предметах) 6. выставка 7. вера 8. роскошь 9. обладание 10. восстанавливать 11.напоминать 12. подходить 13. подозрение 14.быть уволенным  15. выбирать

3. Match the words in two columns and complete the sentences with the phrases.

1. hardly             a) a gardener

2. worth              b) the poor animal

3. employ           c) of restoring

4. suspected        d) of being a spy

5. released          e) comprehensible

1. She was ___________ but the police didn’t have any evidence. 2. Sir Reynolds was reading a long ___________ report written in official language. 3. The old church is certainly ___________ but the community doesn’t have any money to pay the architect and the builders. 4. The new owner of the castle intended to ___________ and the cook. 5. Walking in the forest Sam saw a small white hare under a thick branch and ___________ from the trap.

4. Use the adverbs in brackets in the appropriate forms to complete the sentences.

1. Two very large vans drove quite slowly down the street. The first one was moving a bit (quickly) than the second one. 2. The last orator spoke (enthusiastically) in comparison to the previous speakers. 3. The diggers moved much (far) but didn’t reach  the bottom. 4. I see Uncle Gerald (little) of all my relatives because he seldom comes to Wales. 5.Such species appear (frequently) here than the ones we were speaking about the other day. 6. She began to smile (brightly) than in the days of his youth.

5. Use the derivatives of the words given in brackets to complete the text.

The word “microscope” is a 1.(combine) of two Greek words, micros, or “small” and scopos, or “watcher”. It helps to see tiny things, which are 2.(visible) to the naked eye. No one is quite sure who 3.(actual) invented it. The credit is 4.(usual) given to Galileo. A Dutch 5(science) called Leeuwenhoek is sometimes referred to as “the father of microscope’ but that’s because of many 6(discover) he made with this instrument. He was also the first to see the whole 7(circulate) of the blood. Today the 8(important) of microscope to man in almost every form of science and industry is evident.

3. Match the words in two columns and complete the sentences with the phrases.

1. masterpiece              a) scolar

2. famous                     b) beauty

3. captivating               c) a car

4. perform                    d) miracles

5. hired                         e) is on exhibition

1. In his book “English as a global language” David Cristal, a ___________ and a linguist, showed the role of English in the modern world. 2. Sunflowers Vincent Van Gogh’s ___________in Sweden. 3. Every year Venice’s ___________ attracts thousands of tourists. 4. They say Doctor Lewis can really ___________. Practically all his patients leave his hospital cured and healthy. 5. When we were in Italy, we ___________ for a week.

4. Use the adverbs in brackets in the appropriate forms to complete the sentences.

1. The elderly gentleman spoke to us very dryly, much (dryly) than we had expected him to. 2. You should have acted (slyly). Your opponents are very clever, knowlegeable and cunning. 3. It is snowing hard outside, much (hard) than yesterday. 4. I can say that Ron is a very good athlete. He runs (fast) of all in the team, swims a bit (badly) than Greg and jumps (high) than everybody except Willy.

5. Use the derivatives of the words given in brackets to complete the text.

The word “microscope” is a 1.(combine) of two Greek words, micros, or “small” and scopos, or “watcher”. It helps to see tiny things, which are 2.(visible) to the naked eye. No one is quite sure who 3.(actual) invented it. The credit is 4.(usual) given to Galileo. A Dutch 5(science) called Leeuwenhoek is sometimes referred to as “the father of microscope’ but that’s because of many 6(discover) he made with this instrument. He was also the first to see the whole 7(circulate) of the blood. Today the 8(important) of microscope to man in almost every form of science and industry is evident.

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«Контрольная работа по английскому языку в 11 классе 3 четверть»

A microscope (Greek: μικρόν (micron) = small + σκοπεῖν (skopein) = to look at) is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. Microscopes give us a larger (magnified) image of a tiny object. The microscopes we use in school and at home trace their history back almost four hundred years.

The most common type of microscope—and the first to be invented—is the optical microscope. This is an optical instrument containing one or more lenses that produce an enlarged image of an object placed in the focal plane of the lens(es). However, human creativity, employed in exploring nature, manifested in numerous improvements and new microscope designs, including the electron microscope, scanning probe microscope, field ion microscope, acoustic microscope, and so forth.

The science of investigating small objects using such an instrument is called microscopy, and the term microscopic means minute or very small, not easily visible with the unaided eye; in other words, requiring a microscope to examine. Microbiology is the scientific study of microorganisms, which are forms of life that are microscopic, such as bacteria, fungi, archaea, and protists.

Microscopes extending the range of human visual sensing reveal a world much grander than the world visible to the unaided eye and remind us of how much we cannot know by our own senses. As new microscopes have revealed new layers of the microscopic world successively further and further removed from the human scale, they have raised new challenges of understanding because objects at different scales have their own distinctive behavior properties, sometimes quite different than those at the human scale. When a scanning tunneling microscope, for example, maps the surface of a crystal and shows us a neat array of fuzzy atoms we can get a better visualization of how the atoms may be arranged, but we also need to remember that those fuzzy balls comprise primarily empty space and that we, ourselves, are no more solid at the atomic level than those fuzzy balls in the picture.

History

The first useful microscope is considered to have been developed in the Netherlands in the late sixteenth and early seventeenth century. There is almost as much confusion about the inventor as about the dates. Three different eyeglass makers have been given credit for the invention: Hans Lippershey (who also developed the first real telescope); Hans Janssen; and his son, Zacharias Janssen. Hans Janssen and Zacharias are often said to have invented the first compound microscope in 1590, but this was a declaration by Zacharias Janssen himself halfway through the seventeenth century. The date is certainly not likely, as it has been shown that Zacharias Janssen actually was born around 1590.

By 1609 Galileo Galilei is also credited with inventing a compound microscope with a convex and a concave lens, which he presented to Polish king Sigismund III in 1612.

In 1625 Giovanni Faber of Bamberg (1574–1629) coined the word microscope by analogy with telescope.

Lens quality in early microscopes was often poor so the images were not very clear. But even these rather crude microscopes were a great help in learning more about animals and plants. For example, in 1665, Robert Hooke (1635–1703) published Micrographia, a collection of biological micrographs developed using the compound microscope. Hooked coined the word cell for the structures he discovered in cork bark.

Thonius Philips van Leeuwenhoek, better known as Anton van Leeuwenhoek (1632–1723), was a Dutch tradesman who is well known for his contribution to the improvement of the microscope, as well as his contributions toward the establishment of microbiology. Known as «the father of microbiology,» Leeuwenhoek, using his handcrafted microscopes, was the first to observe and describe single celled organisms that he first referred to as animalcules, and which we now refer to as microorganisms.

Leeuwenhoek’s interest in microscopes began in 1648 in Amsterdam, when he saw a simple microscope, a magnifying glass mounted on a small stand used by textile merchants capable of magnifying to a power of three. It is believed that soon after 1665, he read Robert Hooke’s book Micrographia, and this roused an interest in using microscopes for the purpose of investigating the natural world.

Leeuwenhoek’s interest in microscopy grew steadily until he was spending most of his nights and free time grinding his own lenses, improving the quality of his microscopes, and studying everything he could beneath them. Although he is sometimes erroneously referred to as «the inventor of the microscope,» compound microscopes (with two lenses mounted together) had existed for about three-quarters of a century. However, they were very crude because the technology used made it difficult to build them properly. Leeuwenhoek’s genius was in developing his skill to grind single lenses very precisely. It is likely that his microscopes were powerful magnifying glasses, not compound microscopes.

During his lifetime Leeuwenhoek ground over five hundred optical lenses. He also created over four hundred different types of microscopes, nine of which still exist today. His microscopes were made of silver or copper metal frames holding hand-ground lenses. Those that survived the years are able to magnify up to 270 times. It is suspected, though, that Leeuwenhoek possessed some microscopes that could magnify up to five hundred times.

In the 1860s, Ernst Abbe discovered the Abbe sine condition, a mathematical condition that must be fulfilled by a lens or other optical system in order for it to produce sharp images of off-axis as well as on-axis objects. This offered a breakthrough in microscope design, which until then was largely based on trial and error. The company of Carl Zeiss exploited this discovery and became the dominant microscope manufacturer of its era.

In 1931 Ernst Ruska started to build the first electron microscope, a transmission electron microscope (TEM). In 1936 Erwin Müller invented the field emission microscope, and in 1951 he invented the field ion microscope and was the first to see atoms. In 1967 he added time-of-flight spectroscopy to the field ion microscope, making the first atom probe and allowing the chemical identification of each individual atom.

In 1953 Frits Zernike, professor of theoretical physics, received the Nobel Prize in Physics for his invention of the phase contrast microscope.

In 1981 Gerd Binnig and Heinrich Rohrer developed the scanning tunneling microscope, and in 1986, Binnig, Quate, and Gerber invented the atomic force microscope. In 1988 Alfred Cerezo, Terence Godfrey, and George Smith applied a position-sensitive detector to the atom probe, making it able to resolve atoms in 3-dimensions. Also in 1988 Kingo Itaya invented the electrochemical scanning tunneling microscope, and in 1991, the Kelvin probe force microscope was invented.

Microscope Types

Microscopes can largely be separated into two classes, optical theory microscopes and scanning probe microscopes.

Optical theory microscopes are microscopes that function through the optical theory of lenses in order to magnify the image generated by the passage of a wave through the sample. The waves used are either electromagnetic in optical microscopes or electron beams in electron microscopes. The types commonly used today are the compound light microscope, stereo microscope, and the electron microscope.

Scanning probe microscopes form images of surfaces using a physical probe that scans the specimen. An image of the surface is obtained by mechanically moving the probe in a raster scan of the specimen, line by line, and recording the probe-surface interaction as a function of position.

Optical microscopes

The optical microscope is a type of microscope that uses visible light and a system of lenses to magnify images of small samples. Optical microscopes, through their use of visible wavelengths of light, are the simplest and hence most widely used type of microscope.

There are two basic configurations of optical microscope in use, the simple microscope that uses only one lens for magnification, and the compound microscope that uses a set of many lenses in order to maximize magnification. Recent research [1] has shown that even simple microscopes, those with a single small lens, gave amazingly clear images to the earliest microscopists.

The compound light microscope, in its simplest form—as used by Hooke, for example—would have a single glass lens of short focal length for the objective, and another single glass lens for the eyepiece or ocular. Modern microscopes of this kind are usually more complex, with multiple lens components in both objective and eyepiece assemblies. Today, compound microscopes serve uses in many fields of science, particularly biology and geology.

Optical microscopes use refractive lenses, typically of glass and occasionally of plastic, to focus light into the eye or another light detector. Typical magnification of a light microscope is up to 1,500 times with a theoretical resolution of around 0.2 micrometers. Specialized techniques (e.g., scanning confocal microscopy) may exceed this magnification, but the resolution is an insurmountable diffraction limit.

The stereo or dissecting microscope uses two separate optical paths with two objectives and two eyepieces to provide slightly different viewing angles to the left and right eyes. In this way it produces a three-dimensional (3-D) visualization of the sample being examined. The stereo microscope is often used to study the surfaces of solid specimens or to carry out close work such as sorting, dissection, microsurgery, watch-making, small circuit board manufacture or inspection, and the like.

Electromagnetic wavelengths not visible to human eye

Other microscopes that use electromagnetic wavelengths not visible to the human eye are often called optical microscopes. The most common of these, due to its high resolution yet no requirement for a vacuum-like electron microscope, is the x-ray microscope.

Electron microscopes

Electron microscopes, which use beams of electrons instead of light, are designed for very high magnification usage. Electrons, which have a much smaller wavelength than visible light, allow a much higher resolution. The main limitation of the electron beam is that it must pass through a vacuum as air molecules would otherwise scatter the beam.

Instead of relying on refraction, lenses for electron microscopes are specially designed electromagnets that generates magnetic fields that are approximately parallel to the direction that electrons travel. The electrons are typically detected by a phosphor screen, photographic film or a charge-coupled device (CCD).

Two major variants of electron microscopes exist:

• Scanning electron microscope: looks at the surface of bulk objects by scanning the surface with a fine electron beam and measuring reflection. May also be used for spectroscopy.
• Transmission electron microscope: passes electrons completely through the sample, analogous to basic optical microscopy. This requires careful sample preparation, since electrons are scattered so strongly by most materials. It can also obtain detailed information on the sample’s crystallography through selected area diffraction.

Scanning probe microscope

In scanning probe microscopy (SPM), a physical probe is used either in close contact to the sample or nearly touching it. By rastering the probe across the sample, and by measuring the interactions between the sharp tip of the probe and the sample, a micrograph is generated. The exact nature of the interactions between the probe and the sample determines exactly what kind of SPM is being used. Because this kind of microscopy relies on the interactions between the tip and the sample, it generally only measures information about the surface of the sample.

Some kinds of SPMs are:

• Atomic force microscope
• Scanning tunneling microscope
• Electric force microscope
• Magnetic force microscope (MFM)
• Near-field scanning optical microscope

Point-projection microscopes

The field emission microscope, field ion microscope, and the Atom Probe are examples of point-projection microscopes, where ions are excited from a needle-shaped specimen and hit a detector. The Atom-Probe Tomograph (APT) is the most modern incarnation and allows a three-dimensional atom-by-atom (with chemical elements identified) reconstruction with sub-nanometer resolution.

Acoustic microscopes

Acoustic microscopes use sound waves to measure variations in acoustic impedance. Similar to SONAR in principle, they are used for such jobs as detecting defects in the subsurfaces of materials including those found in integrated circuits.

References

ISBN links support NWE through referral fees

• Dobell, C. (ed.) 1960. Antony van Leeuwenhoek and his «Little Animals. New York: Dover Publications.
• Ford, B. J. 1991. The Leeuwenhoek Legacy. London: Biopress, Bristol, and Farrand Press. ISBN 1850830169.
• Van Berkel, K. “Vermeer, Van Leeuwenhoek en De Astronoom.” Vrij Nederland (February 24, 1996): 62-67.

1

0   0 An optical instrument that augments the power of the eye to see small objects. The name microscope was coined by Johannes Faber (1574-1629) who in 1628 borrowed from the Greek to combined micro-, small with skopein, to view. Although the first microscopes were simple microscopes, most (if not all) optical microscopes today are compound microscopes.

2	0   0 Microscope A microscope that consists of two microscopes in series, the first serving as the ocular lens (close to the eye), and the second serving as the objective lens (close to the object to be viewed).

3

0   0 Microscope A microscope in which an electron beam replaces light to form the image. Electron microscopy (EM) has both pluses (greater magnification and resolution than optical microscopes) and minuses (the observer is not really ‘seeing’ objects, but rather their electron densities, so artifacts may be present).

4	0   0 Microscope A microscope that is equipped to examine material that fluoresces under ultraviolet (UV) light.

5	0   0 Microscope A microscope that has a single converging lens.

6	0   0 Microscope An instrument that is used to look at cells and other small objects that cannot be seen with the eye alone.

7	0   0 Microscope 1650s, from Modern Latin microscopium, literally «an instrument for viewing what is small,» from Greek micro- (see micro-) + -skopion, from skopein «to look, see» (see -scope).

8	0   0 Microscope instrument used to view very small objects by making them appear larger.

9	0   0 Microscope Instrument that provides a magnified view of an object being studied usually by optical means. Electrons, X-rays and ultra-violet light can be used instead of visible light

10	0   0 Microscope magnifier of the image of small objects; "the invention of the microscope led to the discovery of the cell" (microscopic) of or relating to or used in microscopy; &qu [..]

11	0   0 Microscope an instrument with a tube that you look through, which makes very tiny things look much larger

12	0   0 Microscope n. An instrument for assisting the eye in the vision of minute objects or features of objects.

13	0   0 Microscope To dream of a microscope, denotes you will experience failure or small returns in your enterprises.

14	0   0 Microscope instrument that produces an enlarged image of an object. microscopic —

15	0   0 Microscope (n) magnifier of the image of small objects

16	0   0 Microscope A microscope is a very powerful magnifying glass. The entire world – our bodies included – are made up of billions of tiny living things that are so small you can’t see them with just your ey [..]

17	0   0 Microscope A microscope is an instrument which can be used to view objects that are too small to be seen by the naked eye. A microscope can be used to view objects such as bacteria, plants and even human cells.

18	0   0 Microscope An instrument that is used to look at cells and other small objects that cannot be seen with the eye alone.

19	0   0 Microscope An optical instrument that uses a lens or a combination of lenses to produce magnified images of small objects, especially of objects too small to be seen by the unaided eye.

20	0   0 Microscope An optical instrument designed to produce enlarged images of objects. Images are formed by the objective lenses and the object is viewed through eyepieces (oculars). In gemmology, a binocular microsco [..]

21	0   0 Microscope An optical instrument used for observing small objects. * »’1837»’, »The Edinburgh New Philosophical Journal» (volume 23, page 222) *: That he might ascertain whether any of the cloths of anci [..]

Dictionary.university is a dictionary written by people like you and me.
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Add meaning

The word ‘Microscope’ comes from the Latin word ‘Microscopium,’ which is derived from the Ancient Greek word: μικρός, mikrós, meaning»small» and σκοπεῖν, skopeîn, means «to look» or «see».

So, do you know what microscopes are?

The microscope is an instrument used to detect small objects that are invisible to the naked eye and the science behind this investigation is microscopy. 

The use of a microscope is, in interacting with the sample (a crystal/blood sample) and producing images by sending a beam of light/electrons through the sample’s optical path. Also, it helps in detecting photon emissions from a sample, and much more.

On this page, we will understand the use of microscopes with the application of microscopes.

[Image will be uploaded soon]

What is Microscope?

The use of microscope helps us in getting a closer view of exceedingly minute objects that are in the range of  10^-n metres.

The enlarged image can be formed by waveforms including X-ray, acoustic, or electron beam, and be received by direct or digital imaging or by a combination of both methods. 

The microscope can also provide both a dynamic image just like conventional optical instruments and a static, like conventional scanning electron microscopes.

A range of power in which the microscope enlarges the image of the object is the magnifying power, and now we will discuss the same on the page.

Magnifying Power of Microscope Formula

The magnifying power of a microscope formula is a mathematical expression for the number of times the object when examined appears to be enlarged.

We express the magnifying power of the microscope formula in the following manner:

[M=frac{tanbeta }{tanalpha }=frac{text {It is the angle subtended by the final image to the eye}}{text{the angle subtended by the object seen directly}}] (dimensionless ratio)

So, the magnifying power of microscope formula is the ratio of the angle subtended by the final image to the eye to the angle subtended by the object seen directly, provided that both of these are kept at least distance of distinct vision (- 25 cm). 

We call the magnifying power of microscopes the angular magnification.

Here,

tan β ≈ β

tan 𝛼 ≈ 𝛼 

The above two cases are possible when the angles and are very small. So, we rewrite the above equation as;

[M=frac{beta }{alpha }]

Also, M Total = M Objective X M Eyepiece

So, total magnification = magnification of objective * magnification of the eyepiece. 

Now, let’s understand the types of microscopes and the uses of microscopes.

Types of Microscopes

Various types of microscopes that we find in a laboratory are as follows:

1. Simple microscopes

2. Compound microscopes

3. Scanning electron microscopes

4. Transmission electron microscopes

5. Phase-contrast microscopes

6. Interference microscopes

7. Confocal microscopes

8. Stereoscopic microscopes

9. Light microscopes: Dark field microscopes and bright field microscopes

10.  Fluorescence microscopes

11.  X-ray microscope

So, what is the use of a microscope? Let us understand it:

Application of Microscope 

Below, you can see the uses of microscope:

• Microscopes are used in examining the ailments by getting a larger view of the blood sample in detecting the parasites, bacterias attacking the red blood.

• Scientists use a microscope for studying microorganisms, cells, crystalline structures, and molecular structures.

• Microscopes help doctors diagnose the tissue sample.

• The use of a compound microscope is found in examining the following samples:

1. Blood cells

2. Cheek cells

3. Parasites

4. Bacteria

5. Algae

6. Tissue

7. Thin sections of organs

8.  Detecting the UTI (urinary tract infection) in the urine sample

9. Detecting germs

10. Detect crime cases

11. Used in performing research and medical advancements

12. Determine the cause of diseases

13. An aid for prevention of diseases

14. Create electronic devices and circuits

15. Discovery of microorganisms

16. For open branches of sciences

17. In Forensics

In forensics, a microscope is used to study general criminal science, forensic epidemiology, forensic anthropology, and forensic pathology.

In every crime scene, criminals erase all the proofs of their miscreant, so a microscope in Forensic helps doctors examine organs, bones, and other parts of the body to know the cause of the death.

Do You Know?

• A German Physicist named Ernst August Friedrich Ruska designed the first electron microscope. He was conferred with a Nobel Prize in Physics in 1986 for his work in electron optics, including the invention of the electron microscope.

• The first detailed study of the microscopic anatomy of organic tissue, based on the use of the microscope was not discovered until 1644 in Giambattista Odierna’s Locchio Della musca.

• The use of microscopes was widely considered a novelty between the 1660s and 1670s when it was used to study biology by naturalists in England, Italy, and the Netherlands.

The Geography of the USA

The USA is the 4th largest country in the world (after Russia, Canada and China). It is situated in central North America and stretches from the Pacific to the Atlantic Ocean. It borders on Canada in the north and Mexico in the south and has a sea-border with Russia. It also includes Alaska and Hawaii. The total area of the country is 9,4 million square kilometres. The enormous size of the country influences the diversity of landscape, climate and even people.

The USA is a federal republic, a union of 50 states. The capital of the country Washington is situated in a special federal area called the District of Columbia.

The population of the country is about 260 million people. They are the people of all races and nationalities, either descendants of immigrants or immigrants who have come to America from all the countries of the world in search of independence and self-realization. It’s impossible to generalize about the weather, the landscape and the way of living because the nation occupies nearly half of a continent, which is divided into 4 time zones and has almost every type of climate. If you look at the map of the USA you’ll see snow-topped mountains and flat prairies, fertile valleys and deserts, the areas of tropical heat and arctic cold.

One of the most important geographical boundaries in the USA is the 50-centimetre rainfall line, which runs from north to south almost through the middle of the country. East of the line farming, is relatively easy and the population is large. There are man-made irrigation systems, dry farming, grazing and fewer people west of the line.

The West is a mountainous area of the Rocky Mountains, the Cordillera and the Sierra Nevada. The highest peak is Mount McKinley in Alaska (6,000 metres). As compared with the Appalachians in the east, the Rocky Mountains are sharp and. rugged, over 4,000 metres high, rich in gold, copper, lead, silver and other minerals.

The USA has many thousands of streams. Some of them are mighty rivers, which flow lazily across the valleys. Others rush swiftly down deep canyons and steep gorges. The longest are the Mississippi (6,400 kilometres), «the farther of waters»., the Missouri (1,600 kilometres) «too thin to plough and too thick to drink», the Colorado wild, restless and angry, the Columbia full of quiet dignity and the Rio Grand (3,200 kilometres), a national boundary between the USA and Mexico. The Colorado forms the Grand Canyon, which strikes one’s imagination as a fabulous phenomenon of nature. Its perpendicular walls go up to 1,500 metres above the river level. The USA has thousands of lakes of all kinds and sizes. The Great Lakes make up the largest group; they are the greatest collection of fresh water lakes in the world with the total area equal to that of Great Britain,. Here the famous Niagara Falls precipitate from the height of 50 metres. Among salty lakes the Great Salt Lake in Utah and the Salton Sea in California are the most famous. They are rich in salt (6,000 million tons).

The climate of the country varies greatly from arctic in Alaska, through continental in the central part to subtropical in the south. The climate along the Pacific coast is warmer than that of th6 Atlantic coast. The temperature changes little between winter and summer there. In the eastern part the difference between summer and winter is distinct, but not so extreme as in the north central part where the difference between winter and summer is 36 degrees С and even more.

Among the largest cities of the USA are New York, Los Angeles, Chicago, Philadelphia, Detroit, San Francisco and others. But a great proportion of the country consists of open land marked with farm-houses and small towns.

The USA is one of the greatest industrial and leading agricultural nations in the world. With only about 5% of the world’s population and about 6% of its land area, the USA produces around 25% of the world’s industrial products, agricultural goods and services. It’s the world’s leader in biochemical and genetic engineering, aerospace research and development, communications, computer and information services and similar high-technology fields. One of the reasons is America’s vitality, its spirit of enterprise and initiative as well as its size and natural resources.

География США

США является 4-й крупнейшей страной в мире (после России, Канады и Китая). Он расположен в центральной части Северной Америки и простирается от Тихого до Атлантического океана. Это граничит с Канадой на севере и Мексикой на юге и на море-границы с Россией. Она также включает Аляску и Гавайи. Общая площадь страны составляет 9,4 миллиона квадратных километров. Огромный размер страны влияет на разнообразие ландшафта, климата и даже людей.

США-Федеративная Республика, Союз 50 государств. Столица страны Вашингтон находится в специальном федеральном округе под названием округ Колумбия.

Население страны составляет около 260 миллионов человек. Это люди всех рас и национальностей, либо потомки иммигрантов или иммигрантов, которые приехали в Америку из всех стран мира в поисках независимости и самореализации. Нельзя обобщать по поводу погоды, ландшафта и образа жизни, потому что страна занимает почти половину континента, который разделен на 4 часовых поясов и имеет практически все виды климата. Если вы посмотрите на карту США, вы увидите заснеженные горы и плоские степи, плодородные долины и пустыни, районы тропической жары и арктического холода.

Одним из самых важных географических границ, в США-50 сантиметров осадков в виде линии, идущей с севера на юг почти через середину страны. К востоку от линии сельского хозяйства, сравнительно легко и с большим населением. Есть рукотворные оросительные системы, земледелие, выпас и меньше людей к западу от линии.

На Западе гористая местность Скалистые горы, Кордильеры и Сьерра-Невада. Самая высокая вершина-гора Мак-Кинли на Аляске (6 000 метров). По сравнению с Аппалачей на востоке, Скалистые горы и острые. прочный, более 4000 метров, богата золотом, медью, свинцом, серебром и другими минералами.

США уже много тысяч потоков. Некоторые из них мощные реки, которые текут лениво по долинам. Другим стремительно мчаться вниз, глубоких каньонов и крутых ущелий. Самый длинный Миссисипи (6,400 км), «чем дальше от воды»., Миссури (1600 км) «слишком тонкий, чтобы плуг и слишком густая, чтобы пить», «Колорадо» дикие, беспокойные и злые, Колумбия, спокойное достоинство и Рио-Гранд (3,200 км), Национальный граница между США и Мексикой. Колорадо образует большой каньон, который поражает воображение как сказочное явление природы. Его перпендикулярные стены поднимаются до 1500 метров над уровнем реки. США имеет тысячи озер всех видов и размеров. Великие озера составляют самую большую группу; они-самая большая коллекция пресноводных озер в мире с общей площадью, равной Великобритании. Здесь знаменитый Ниагарский водопад осадок с высоты 50 метров. Среди соленых озер Большое Соленое озеро в штате Юта и Солтон-Си в Калифорнии, самый известный. Они богаты солью (6 000 млн. тонн).

Климат в стране значительно варьируется от Арктического на Аляске, через континентальный в центральной части до субтропического на юге. Климат вдоль тихоокеанского побережья теплее, чем у атлантического побережья сегментов th6. Температура мало меняется между зимой и летом нет. В восточной части разницы между летом и зимой отличается, но не так экстремально как в северо-центральной части, где разница между зимой и летом 36 градусов С и даже больше.

Среди крупнейших городов США Нью-Йорк, Лос-Анджелес, Чикаго, Филадельфия, Детройт, Сан-Франциско и другие. Но большую часть страны состоит из открытой земли, помеченные усадеб и небольших городах.

США является одним из крупнейших промышленных и ведущих аграрных держав в мире. Лишь около 5% мирового населения и около 6% ее территории, США производит около 25% промышленной продукции в мире, сельскохозяйственных товаров и услуг. Это мировой лидер в области биохимии и генной инженерии, аэрокосмических исследований и развития, коммуникаций, компьютерных и информационных услуг и аналогичные высокотехнологичных отраслях. Одна из причин-живучесть Америки, ее дух предпринимательства и инициативы, а также ее размеры и природные ресурсы.

1. Read the text and complete it with the phrases (a-h). There is one phrase you don’t have to use.
2. a) surgeon operates the instruments
3. b) by an electronic device
4. c) the building of surgical robots
5. d) because they can detect the change in acidity
6. e) becomes more difficult
7. f) on a special screen
8. g) the operation can be done faster
9. h) safe are these robots

Now there are robots that help surgeon perform operations. What can they do and is there anything to fear?

As surgical techniques become more advanced, keeping close control over everything that goes on during the operation (1)_e_ . The need for greater control and sensitivity has led to (2)_c_. Keyhole surgery has s lot of benefit from their help. Specially adapted instruments on the ends of thin tubes are put through a small hole in the patient’s skin. The (3)_a_ from outside the body using an instrument called a laparoscope, which has a camera on it. Thus doctors can watch the whole operation (4)_f_.

The Laparobot or the robot laparascope gives the surgeon greater control over the image on the screen, so (5)_g_. The Laparobot is controlled (6)_b_ worn by the surgeon. The position of the camera inside the patient follows the surgeon’s hands movements. But how (7)_h_? Unlike industrial robots, these new surgical robots are designed to be extremely sensitive to the environment and respond quickly to any change. For instance, they stop if they bump into an unexpected blood vessel.

*b – excess.

1. Use the adverbs in brackets in the appropriate forms to complete the sentences.
2. Two very large vans drove quite slowly down the street. The first one was moving a bit quickerthan the second one. 2. The last orator spoke more enthusiastically in comparison to the previous speakers. 3. The diggers moved muchfarther but didn’t reach the bottom. 4. I see Uncle Gerald least of all my relatives because he seldom comes to Wales. 5. Such species appear more frequently here than the ones we were speaking about the other day.  6. She began to smile brighter than in the days of his youth.

1. Use the derivatives of the words given in brackets to complete the text.

The word “microscope” is a 1.combination of two Greek words, micros, or “small” and scopos , or “watcher”. It helps to see tiny things, which are 2.invisible to the naked eye. No one is quite sure who 3.actually invented it. The credit is 4.usually given to Galileo. A Dutch 5.scientist called Leeuwenhoek is sometimes referred to as “the father of microscope’ but that’s because of many 6.discoveries he made with this instrument. He was also the first to see the whole 7. circulation of the blood. Today the 8. importance of microscope to man in almost every form of science and industry is evident.