1. A great series of chemical changes has to occur before foods become protoplasm.
2. These plant parts may have been found on and below the soil surface.
3. All measurements should be made with great accuracy.
4. There may be other elements present in some proteins, e.g. magnesium.
5. This means that there must be harmony among all the genes which a population contains.
6. This list could be extended a long way.
7. Yet, again and again, something new must have been introduced into the inheritance if all the higher forms of life that exist today had their origin in such lowly ancestor as Amoeba.
8. This quality was lacking in English wheat, and therefore grain had to be imported from Ameria and Canada.
9. Living protoplasm must always be thought as a system in dynamic equilibrium.
10. There should be an equal chance of Xor Y sperm meeting an ovum, and therefore equal members of boy and girl babies should be born.
11. Different techniques again have to be used with microorganisms.
12. This implies that each DNA chain might serve as a template for the synthesis of its complementary pair, and in this way the structure of the molecule could be reduplicated exactly.
13. Nevertheless, "hybrids" made between bacterial strains with different characteristics may show characteristics from both parents.
14. All the laboratory vessels have to be carefully washed before using them for any experiments.
15. The development of this disease must have been considerably favoured by high moisture conditions.
Ex. 2. Choose and use the appropriate modal verb from given in the brackets.
1. Our brain interprets the impulses and (need, to have to, should, can, must) tell where they are coming from and to what they are referring.
2. White-rod fungi (need, to have to, should, can, must) oxidize lignin due to release of enzymes.
3. You cant park your car here for nothing. You (neednt, must, mustnt, has to) pay.
4. Ian doesnt (can, would, have to, might, must) work very hard. He has got an easy job.
5. (Would, need, may) changes in the structure within nucleus drive differentiation of cells?
6. As we learn more about the chemical signal used by marine organisms, we (need, may, can, would) now think about using these signals to allow human activities to be carried out without damage to the marine environment.
7. Different parts of the tongue (would, should, need, can) detect all types of tastes.
8. A receptor (would, should, need, can, may) respond to the other tastes, but it responds in the strongest way to a particular taste.
9. (Neednt, ought, could) you give us a consultation tomorrow?
10. To protect environment serious measures to create a system of ecological security (can, may, should) be taken.
11. (Can, ought, need, have) she have been waiting for us all the time?
12. Initial steps to preserve environment are absolutely insufficient and they (can, must, may) be carried onward.
13. Contact lenses were made of methacrylate and (could, would) be easily inserted and taken out.
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14. Even the first artificial kidney invented by Dutchman Willem Kolff in 1945 (can, must, would, could) be used for purifying the blood of human being.
15. Mendeleyev found it necessary to alter some atomic weights so that the elements (can, must, should) fall into positions in the periodic table assigned to them by their chemical properties.
Ex. 3. Open the brackets. Use the modal verbs in the appropriate forms and tenses.
1. Such plants (must, to cultivate) by a man long ago.
2. Genetic engineers (to be able, to remake) parasite insects to prevent the spread of diseases.
3. The genetically modified insects immune system reacts to the pathogenic organism and kills it before it (can, to transfer) to humans.
4. We (to be to, to meet) at the entrance of the theatre at a quarter to seven, but he didnt come.
5. What (should, to do) to preserve our wild flowers?
6. At the University of Cambridge Darwin (couldn't, to make) himself care for anything but hunting and natural history.
7. Pasteur (to be to, to use) this technique in preparing a vaccine which protected cattle against anthrax ( ).
8. Before Eijkman (could, to do) much about chickens disease very much like beriberi, the disease vanished.
9. Life (would, to be) impossible without proteins since protoplasm is made of them.
10. You (ought, to plant) this seed in spring.
11. The soil (should, to be) fine and moist.
12. (Need I, to carry out) the lab work?
13. (Could you, to help) me to unload the car?
14. The test tubes arent dirty, so you (neednt, to clean) them.
15. We (not to have to, to study) botany yesterday, the credit test was delayed.
Ex. 4. Translate from Russian into English.
1. .
2. .
3. .
4. , 300 ?
5. , .
6. , , 0,5 .
7. , .
8. , .
9. .
10. .
11. .
12. ?
13. .
14. , .
15. (exhaustion) - !
16. , .
17. .
18. , , .
19. , .
20. , .
21. , .
22. . ( ).
23. ?
24. . ?
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25. () .
26. , .
27. .
28. , ( ) .
29. , .
30. .
Ex. 5. Supply the necessary modal verbs.
1. The roots of this plant ( ) for human food.
2. You ( ) the characteristics of both plants as there ( ) a considerable difference between them.
3. Id like to read Anns letter. The only problem is I ( ) my glasses.
4. You ( ) him with this homework. Its important that he does it himself.
5. I just want a general idea of the article so I ( ) all the text.
6. Why did you wash this shirt? It was not dirty, you ( ) it.
7. I dont think you ( ) TV so much.
8. We ( ) home last night. There were no buses.
9. I dont want the children to play in this room. They ( ) something.
10. Im sorry that I didnt take your advice. I ( ) this letter a week ago.
11. Our teacher says that we ( ) English fluently in a few month.
12. Paul doesnt like his new job. Sometimes he () work at weekends.
13. This restaurant ( ) very good. Its always full of people.
14. Cigarette smoke contains thousands of chemical agents, many of them () cause cancer, so smoking ( ).
15. All animals ( ) other organisms or their products to survive.
16. The professor insisted on her repeating the experiment, but she ( ).
UNIT 11
GRAMMAR: CONDITIONALS.
TEXT: PROTISTA.
PRE-READING AND READING TASKS
1. Make sure you know the following words:
| diverse | [daI'vE:s] | |
| to persist | [pq'sIst] | |
| ancestry | ['xnsqstrI, 'xnsestrI] | , |
| arbitrary | ['Q:bItrqrI] | |
| lineage | ['lInIIdZ] | , |
| to dispense with | [dIs'pens] | |
| descendant | [dI'sendqnt] | |
| immediate | [I'mi:dIqt] | , |
| to spin (spun, span; spun) | [spIn] | , |
| diatom | ['daIqtPm] | |
| discrepancy | [dIs'krep(q)nsI] | , |
