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Архитектура Аудит Военная наука Иностранные языки Медицина Металлургия Метрология Образование Политология Производство Психология Стандартизация Технологии |
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Архитектура Аудит Военная наука Иностранные языки Медицина Металлургия Метрология Образование Политология Производство Психология Стандартизация Технологии |
How the greenhouse effect works⇐ ПредыдущаяСтр 22 из 22
Gases like (1) carbon dioxide are important for the Earth's temperature. They let heat from the Sun reach the ground, and keep it there. In this way, they help to keep the Earth's temperature at the ideal level. However, human activities are destroying the natural (2)............of these gases. When we burn fossil fuels like (3).............oil and gas, we produce too much carbon dioxide (CO2). This CO2 collects in the atmosphere and (4)............too much heat. We make the problem worse when we cut down (5).............Living trees absorb carbon dioxide and (6)............ oxygen, but when we cut trees down we release carbon dioxide back into the atmosphere. Exercise 16. Replace the words in italics with a phrasal verb from the box in the correct form. There are two verbs that you won't need.
1. Our planet is in great danger. We all need to accept and deal with the challenges if we are to avoid disaster. 2. We will probably no longer have enough oil in the next 60 years, so we need to develop renewable energy sources such as wind power. 3. Natural resources like wood and coal are being finished at an ever-increasing rate. 4. We ought to reduce the amount of energy we use; for example, we should switch off lights when we leave a room. 5. We ought to stop using cars for unnecessary journeys and use public transport instead.
Exercise 17. Underline the correct word in each pair. Then answer the questions with a partner.
1. How many species/forms of birds can you name in English? 2. Which animals may become vanished/extinct in the near future? 3. What kinds of crops are grown/grown up in your country? 4. What do scientists mean by soil/earth erosion and what causes it? Is it a problem in your country? 5. What sort of animals and fish live off the coast/beach of your country, e.g. whales, dolphins? 6. What happens to wildlife if oil tankers dump/drop oil in the seas? 7. Have you had any wildlife catastrophes/misfortunes related to pollution in your country recently? Exercise 18. Read the text ignoring the gaps for the moment.
1. What information does it give about the causes and effects of global warming? 2. According to the text, what will happen if we don't do something about it now?
Exercise 19. Now complete the exam task. Read the gapped sentences very carefully. Remember, to help you choose the right word, you should: • pay careful attention to meaning. • be aware of grammatical patterns such as prepositions after nouns and verbs, and infinitives after verbs. • look out for collocations and fixed phrases. • make sure that linking words fit the meaning of the text.
Exercise 20. Read the text below and decide which answer A, B, C or D best fits each space. There is an example at the beginning (0). 0 A recognized B regarded C registered D represented GLOBAL WARMING The Earth's climate is a very complicated system. What's more, it is now widely (0).A. that human activity is having an effect on it. The pollution which (1).....from the use of oil and coal in industry, (2).....the increased use of private cars, is causing significant changes in temperature in many parts of the world. These changes often have a knock-on effect on other aspects of the climate, (3).....to things like extreme weather (4).....and rising sea levels. Studying the changes which are taking (5).....and predicting those that are (6).....to happen in the future is now a major area of scientific research. The information which the scientists (7).....is very useful in helping governments to (8).....the effects of climate change and so be better prepared to (9).....with them. A much more (10).....problem, however, is how to prevent the situation from (11).....worse. This depends on how quickly, and to what extent, the (12).....of pollution in the atmosphere increases. Although many countries have now agreed to try and limit the pollution they create, much more (13).....to be done. If no further action is (14)......then temperatures are set to rise by about 0.2% per decade (15).....the 21st century. Such a rate of warming is greater than anything that has occurred over the last ten thousand years.
Exercise 21. Read the whole text again and find: 1. four examples of verb + particle or preposition 2. two collocations with take 3. one collocation with have Тексты для самостоятельной работы студентов: 1. Л.В. Хведченя, Р.В. Хорень «Английский язык для поступающих в вузы», Минск, 1996, стр. 164 – My biography; стр. 170 – My family. 2. И.В. Цветкова, И.А. Клепальченко, Н.А. Мыльцева «Английский язык для школьников и поступающих в вузы», Москва, 1996, стр. 96 – My family; стр. 102 – My friend; стр. 152 – Mozart; стр. 158 – Albert Einstein. 3. И.П. Агабекян, П.И. Коваленко «Английский для технических вузов», Ростов-на-Дону, 2004, стр. 23-25 – My biography after Mark Twain.
Part 16. Научно-технический прогресс. История науки. Знаменательные научные открытия прошлого. Exercise 1. Read the text. ATOMS, MOLECULES AND COMPOUNDS Water is abundant on Earth today - as a gas, as a liquid, and as a solid. The physical state of water depends on temperature. If the temperature is high enough, water is a gas. If the temperature is low enough, water freezes to ice. Although the forms of water may vary, its chemical compositions remains the same. Water has some unusual physical and chemical properties that have had a powerful effect on the evolution of life. A close look at the chemistry of water can provide information about the chemical nature of matter and about the function of biological organisms.
Suppose you found a way to subdivide a drop of water into smaller and smaller droplets until you could not even see them under a microscope. No matter how small the water droplet, it would still be made of identical units called molecules. Molecules of water are the smallest units into which water can be subdivided and still have the essential chemical properties of water. When an electric current flows through water under proper conditions, a remarkable change occurs: water becomes two gases. One is the lightest gas, hydrogen, which burns with a very hot flame in air. The other gas is oxygen. Any burning object thrust into oxygen will continue to burn with a more brilliant flame. Thus, under certain conditions, water molecules can break down into two different substances, hydrogen and oxygen. Neither hydrogen nor oxygen has the appearance or any other property of water. Molecules are made of atoms that have been chemically combined. Molecules may be made from more than one kind (as in water), or they may be made from atoms of the same kind. For example, hydrogen gas consists of hydrogen atoms that exists in combination with each other. A molecule of hydrogen has two hydrogen atoms. The same arrangement is true of an oxygen molecule, which has two oxygen atoms (Oxygen also forms molecules of ozone that contain three atoms of oxygen). A substance made of only one kind of atom is called an element. More than 100 different elements are known today. A substance made of two or more different kinds of atoms, such as water, is called a compound. Elements can combine chemically in many ways to form the millions of compounds that give Earth variety of materials. Chemists have given each element a symbol of letters from the element’s name. H stands for hydrogen, O for oxygen, C for carbon, and N for nitrogen. Iron, however, is Fe, derived from the word ferrum, reflecting that some symbols come from an element’s Latin or Greek name. Exercise 2. Master the active vocabulary: hydrogen [´ haidr∂ d (∂ )n] - водород nitrogen [´ naitr∂ d (∂ )n] - азот oxygen [´ oksid (∂ )n] - кислород carbon [´ ka: b(∂ )n] - углерод ozone [´ ∂ z∂ n] - озон compound [´ kompa nd] - состав, соединение
Exercise 3. Answer the questions:
1) What does the physical state of water depend on? 2) Under what conditions does water freeze to ice? 3) What are molecules? 4) What remarkable change occurs when an electric current flows through water? 5) What does hydrogen gas consist of? 6) What is an element? 7) How many elements are known today? Exercise 4. Give English equivalents for the following: жидкость; химические свойства воды; мельчайшие частицы; электрический ток; водород; кислород; соединение; отражать.
Exercise 5. Give Russian equivalents for: to freeze to ice; to have a powerful effect on; biological organisms; under proper conditions; to derive. Exercise 6. Read the text. CHEMICAL REACTIONS AND CHEMICAL BONDS. When two or more atoms react to form compounds, chemical bonds are formed by the attraction, sharing, or transfer to outer electrons from one atom to other. Such bonds between atoms can be broken, the atoms rearranged, and new bonds formed. A chemical reaction involves the making and breaking of chemical bonds. Chemical reactions are always occurring in living organisms. Living organisms are sometimes compared to chemical factories, bat the number and complexity of chemical reactions that occur in living organisms are vastly greater than in factory. In chemical reactions, substances interact and form new bonds and new substances. These events are important in a cell for two reasons. First, chemical reactions are the only way to form new molecules that the cell requires for such things as growth and tissue maintenance.
Second, the making and bracing of bonds involves changes in energy. As a result of chemical reactions in a cell, energy may be stored, used to do work, or released. When atoms interact, they can form several types of chemical bonds. One type forms when electrons are transferred from one atom to another. This type of chemical bond occur in many substances, including table salt, also known as sodium chloride (NaCl). As the latter name suggests, table salt is made of two elements, sodium (Na) and chlorine(Cl). When atoms of these two elements react, an electron passed from a sodium atom to a chlorine atom. The resulting sodium atom is positively charged, for it has one less electron than protons. It becomes a sodium ion, written as Na+. The chlorine atom is negatively charged, for it has one more electron than protons. It becomes a chloride ion, written as Cl-. Note the change in name from chlorine to chloride. As these examples suggest, an ion can be defined as an atom or a group of atoms that has acquired a positive or negative charge as a result of gaining or losing one or more electrons. By this definition molecules as well as atoms can become ions by gaining or losing electrons. Table salt consists of positively charged sodium ions and negatively charged chloride ions, each strongly attracted to the other. The attraction between oppositely charged ions forms an ionic bond.
The chemical behavior of water indicates that the atoms do not share the electrons equality. The larger oxygen atom attracts the electrons more strongly than the smaller hydrogen atoms do. In the electrons of a bond are not shared equally, the bond is called a polar covalent bond. In contrast, the electrons in a molecule of hydrogen gas are shared equally, and the resulting covalent bond is said to be nonpolar. Polar molecules may form still another type of chemical bond. An attraction can occur between a slightly positive hydrogen atom in a molecule and a nearby slightly negative atom of another molecule (or of the same molecule if it is large enough).This type of attraction is called a hydrogen bond. Exercise 7. Master the active vocabulary: bond [bond ] - связь, соединение electron [i´ lektron ] - электрон tissue [´ ti u: ] - ткань chloride [´ kl: raid] - хлорид sodium [´ s∂ di∂ m] -натрий chlorine [´ kl: ri: n ] - хлор ion [´ ai∂ n] -ион proton [´ pr∂ ton] - протон Exercise 8. Answer the questions: 1) What does a chemical reaction involve? 2) In what organisms are chemical reactions always occuring? 3) What do substances form in chemical reactions? 4) What does the making of bonds involve? 5) How many types of chemical bonds can atoms form when they interact? Enumerate them. 6) What does table salt consist of? 7) What does the chemical behavior of water indicate? 8) What type of attraction is called a hydrogen bond? Exercise 9. Put an appropriate expression in each blank.
1. When two or more atoms............. compounds, chemical bonds are formed by............., or transfer to outer electrons from one atom to other. 2. In chemical reactions, substances............. and............. new bonds and new substances. 3. As a result of chemical reactions in a cell, energy............. used to do work, or released. 4. The resulting sodium atom............, for it has one less electron than protons. 5. The attraction between............. forms an ionie bond. ORGANIC COMPOUNDS AND LIFE Many chemical compounds besides water are needed for life to exist. The most important are organic compounds.Chemically speaking organic compounds are carbon compounds in which the carbon atoms are combined with hydrogen and usually oxygen.Organic compounds also frequently contain nitrogen, sulfur, or phosphorus.A few carbon compounds have never been included with organic compounds: carbon dioxide (C O ), carbon monoxide (C O), and carbonic acid (H C O ). The name «organic» was coined long ago when it was thought these compounds could be formed only by living cells.Since then millions of different organic compounds have been synthesized in the laboratory. There is no longer any reason to call these compounds «organic», but the name is so well established that it is widely used to describe nearly all carbon compounds, essential for life or not. Carbon can combine in long chains that form the backbone of large, complex molecules or macromolecules. The backbone of carbon atoms is called the carbon skeleton. Other atoms and molecules can attach to the carbon skeleton, giving each macromolecule a particular structure and, therefore, a particular function.The following sections of the chapter discuss the characteristics of the four most important classes of macromolecules-carbohydrates, lipids, proteins, and nucleic acids. Exercise 10. Master the active vocabulary: compound [´ kompa nd] - состав, соединение hydrogen [´ haidr∂ d (∂ )n] - водород oxygen [´ oksid (∂ )n ] - кислород nitrogen [´ naitr∂ d (∂ )n] - азот carbon [´ ka: b(∂ )n] - углерод
Exercise 11. Answer the questions: 1) What are organic compounds? 2) What elements do organic compounds contain? 3) When was the name «organic» coined? 4) What is a carbon skeleton? Exercise 12. Find English equivalents for: органические соединения; существовать; углеродные соединения; создавать (новые слова, выражения); основа. Exercise 13. Read the text. CARBOHYDRATES All known types of living cells contain carbohydrates (KAR both HY drayts; carbo = carbon, hydrate =water). In addition to carbon atoms, carbohydrates contain hydrogen and oxygen atoms in the same two-to-one ratio as water. The simplest carbohydrates are single sugars called monosaccharides (MON oh SAK uh rydz). Most organisms readily use the monosaccharide glucose (also called blood sugar) as a source of energy.
Biologically important sugars often have a phosphate group attached to the carbon skeleton and are called sugar phosphates. The phosphate group, which is composed of an atom of phosphorus and three atoms of oxygen, is shown as P when attached to a carbon skeleton. For example, glucose-6-phosphate, which has important roles in the cells, has a phosphate group attached to its sixth carbon atom. Several glucose molecules may bond together to build complex carbohydrates called polysaccharides(POL ee SAK uh rydz ).Starch and cellulose are the complex are the complex carbohydrates commonly formed by plants. Starch is an energy-storage and carbon-reserve compound in many plants and is an important food source for humans.The rigid walls surrounding plant cells contain cellulose, an important part of wood and cotton fibers.The human liver and muscles store carbohydrates in the form of glycogen (GLY ko jen ), also called animal starch.Molecules of starch, cellulose, and glycogen consist of thousands of glucose units and have no fixed size. Exercise 14. Master the active vocabulary: carbo-hydrate [ka: b∂ ´ haidreit] - углевод glucose [´ glu: k∂ s] - глюкоза phosphate [´ fosfeit ] - фосфат phosphorus [´ fosf(∂ )r∂ s ] - фосфор starch [sta: t ] - крахмал cellulose [´ selj l∂ z ] - целлюлоза, клетчатка fiber [´ faib∂ ] - волокно, фибра Exercise 15. Answer the questions: 1) What atoms do carbohydrates contain? 2) What do most organisms use as a source of energy? 3) What are sugar phosphates? 4) What is starch? 5) What is cellulose? Exercise 16. Change the order of ideas to that actually used by the author: 1. The rigid walls surrounding plant cells contain cellulose, an important part of wood and cotton fibers. 2. The simplest carbohydrates are single sugars called monosaccharides. 3. Several glucose molecules may bond together to build complex carbohydrates called polysaccharides. 4. All known types of living cells contain carbohydrates. 5. Starch and cellulose are the complex carbohydrates commonly formed by plants. 6. Molecules of starch, cellulose, and glycogen consist of thousands of glucose units and have no fixed size.
CONTENTS Part 1. Знакомство. 3 Part 2. Путешествия. Различные виды путешествий и их характеристики. 12 Part 3. У врача. Медицинское обслуживание. 33 Part 4. Моя страна. Мой город. Достопримечательности. 43 Part 5. Страны изучаемого языка (Великобритания, США, Австралия, Новая Зеландия): географические, политические и культурные аспекты. 58 Part 6. Наш университет. Высшее образование в России. 79 Part 7. Высшее образование в стране изучаемого языка. Ведущие мировые университеты. 86 Part 8. Покупки. В магазине. 108 Part 9. Война и мир. Угроза терроризма. 119 Part 10. Страны третьего мира. Проблемы миграции. 126 Part 11. Информатизация общества. 151 Part 12. Область моих научных интересов. 169 Part 13. Современные достижения науки. Перспективы развития науки. 194 Part 14. Выдающиеся учёные прошлого. 216 Part 15.Экологические проблемы Астраханского региона, России и мира в целом. 232 Part 16.Научно-технический прогресс. История науки. Знаменательные научные открытия прошлого. 242 |
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(a) In solution, glucose, a 6-carbon sugar, can exist in two forms: a straight chain and a ring form. The ring form, in which 5 carbon atoms and an oxygen atom form a closed ring, is by far the most abundant. (b) The two forms of glucose-6-phosphate.