VI. Restate the following sentences according to the pattern.

A. Change into negative.

Example: The virus has invaded the cell.

The virus has not invaded the cell.

1. The virus has invaded the cell.

2. Some infections have weakened him for three months.

3. The scientists have found the parasites.

4. The outer coat of the virus has been stripped.

B. Give short answers.

Example: Has the spiral turned to the right?

Yes, it has./ No, it hasn’t.

1. Has the exact nature of viruses been settled yet?

2. Have you found any similarities between genes and chromo­somes?

3. Have they measured viruses?

4. Has virus duplication been studied thoroughly?

C. Change into questions supplying short answers. Example: They have measured viruses.

Have they measured viruses?

1. Modem medical science has made great advances in the inves­tigation of the causes of disease.

2. The diseases of the mother have affected the developing em­bryo.

3. The smoking of two cigarettes a day has not retarded the normal growth of the foetus in the womb.

4. Malaria has resulted in neither chronic ill health nor death.

5. I have never had measles.

D. How much ? or How many? Example: She has two children.

How many children does she have?

1. They have a lot of test tubes.

2. They can give me some information about cloned sheep.

3. Peter has studied the congenital causes of disorders this semes­ter.

4. We bought a new microscope last week.

5. Our laboratory has got lots of microscopes.

6. Some deformities may be due to drugs taken during preg­nancy.

7. He knows a lot about chromosomes.

8. She earns $20,000 a year.

E. Write these sentences in the negative, using “much” or “many”.

Example: I’ve got a lot of time.

I haven’t got much time.

1. There are a lot of bacteria in the sample.

2. He used a large amount of yeast to brew his beer.

3. They’ve got plenty of “donors”.

4. Susan told me lots of news.

5. He can drink a great deal of wine.

6. There was a large quantity of blood on his face.

7. I saw a great many nuclei.

8. The doctors were fertilizing lots of eggs.

VII. For or since?

Put for or since into each gap.

1. Bacteria have flourished on earth millions of years.

2. We have been learning to domesticate them __ a while.

3. Microbes have colonized your body the moment you were born.

4. I’m looking at the molds. They have been on the slide of microscope __ 13.00 this afternoon.

5. We have known Lee Silver several weeks.

6. He has been a molecular biologist __ he finished the university.

7. Peter has had malaria ___ he went to Africa.

8. The patients have suffered from vitamin deficiency disease ___ six months.

VIII. Rearrange these series of words to form sentences ( or questions).

Example: bacteria / convert / into / bread / sugars / some.

Some bacteria convert sugars into bread.

1. smallest / viruses / the / are / microbes.

2. become / fashionable / a / diagnosis / has / it / medical.

3. They / identified / ever / have / virus / that?

4. rickettsia / filters / never / porcelain / let / through.

5. act / bacteria / where / usually / do?

6. the / damaged / has / the / kidneys / already / virus.

7. survival / depend / only / will / on / time / the / therapies.

8. just / exercise /I / finished / this / have.