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2. Сопоставьте глаголы из текста с их русскими эквивалентами.

1. mean

2. grow

3. reproduce

4. infect

5. know

6. discover

7. describe

8. consist

9. have

10. make

11. carry

12. protect

13. surround

14. vary

15. study

16. evolve

17. move

18. cause

19. include

20. continue

21. eliminate

22. produce

23. give

24. develop

25. treat

a. заражать

b. переносить

c. воспроизводить (ся)

d. защищать

с. означать

f. разрабатывать

g. делать открытие

h. изучать

i. знать

j. продолжать

k. расти

l. состоять

m. делать

n. быть причиной

о. давать

р. вырабатывать

q. различаться

г. лечить

s. передвигаться

t. иметь

u. описывать

v. окружать

w. включать в себя

х. ликвидировать

у. развиваться

3. Прочитайте текст и ответьте на следующие вопросы.

1. What is virus?

2. What is virology?

3. Who discovered the first virus?

4. What parts do viruses consist of?

5. What do you know about the size and shape of viruses?

6. How do they appear and spread?

7. Do all viruses cause diseases?

Virus

A virus (from the Latin virus meaning toxin or poison) is a sub- microscopic infectious agent that is unable to grow or reproduce outside a host cell. Viruses infect all cellular life. The first known vi­rus, tobacco mosaic virus, was discovered by Martinus Beijerinck in 1898, and now more than 5,000 types of virus have been described. The study of viruses is known as virology, and is a branch of micro­biology.

Viruses consist of two or three parts: all viruses have genes made from either DNA (deoxyribonucleicacid) or RNA (ribonucleic acid), long molecules that carry genetic information; all have a protein coat that protects these genes; and some have an envelope of fat that sur­rounds them when they are outside a cell. Viruses vary in shape from simple helical and icosahedral shapes to more complex structures.

They are circa 100 times smaller than bacteria. Most viruses that have been studied have a diameter between 10 and 300 nanometres. The origins of viruses are unclear: some may have evolved from plas­mids — pieces of DNA that can move between cells, others may have evolved from bacteria.

Examples of common human diseases caused bv viruses include the common cold, influenza, chickcnpox, and cold sores.

Not all viruses cause disease, as many viruses reproduce without causing any obvious harm to the infected organism. Some viruses such as hepatitis В can cause life-long or chronic infections, and the viruses continue to replicate in the body despite the hosts’ defense mechanisms. However, viral infections in animals usually cause an immune response, which can completely eliminate a virus. These immune responses can also be produced by vaccines that give life­long immunity to a viral infection. Microorganisms such as bacteria also have defenses against viral infection, such as restriction modi­fication systems. Antibiotics have no effect on viruses, but antiviral drugs have been developed to treat life-threatening and more minor infections.