Exercise 6. Define the forms of infinitive and translate the sentences into Ukrainian.

• The doctor wanted to examine the patient in the morning.

• To know Anatomy well is necessary for every surgeon.

• Our students came to the Institute to listen to the lecture on bones.

• My friend was the first to have taken the examination in Biology.

• The surgeon will begin to be operating on this patient at 10 o’clock.

• He wants to determine the direction of muscular fibers.

• Microbiology is one of the most interesting subjects to study.

• He seems to have finished his work.

• The weather seems to be improving.

• He is known to have been working on this problem for many years.

Exercise 7 a)Read and translate the following word combinations; b). Make up the sentences of your own.

Certain microbes; antibiotic sub­stances; live in the air, soil, and water; to fight various diseases; harmful to the cells; bacterial diseases; streptococcal bacteria; to attack human cells; the process of dividing; to treat infectious diseases; livestock feed; to stimu­late the animals’ growth; pathogenic microbes.

Exercise 8 a)Read and translate the text; b) Find in the text the sentences with Infinitive.

Antibiotics

Antibiotic is a drug produced by certain microbes. Antibiotic sub­stances are obtained from bacteria and fungi that live in the air, soil, and water. Most antibiotics are used by physicians to fight various diseases caused by harmful microbes. A few are used to treat certain cancers.

Antibiotics are selectively toxic — that is, they damage certain types of cells, but do not damage others. Many antibiotics are harmful to the cells of pathogenic (disease-causing) microbes, but they do not normally damage human cells. Physicians use these types of antibio­tics to treat a variety of bacterial diseases, including gonorrhea, syphi­lis, and tuberculosis, and infections caused by staphylococcal and streptococcal bacteria. A small number of antibiotics, however, were developed to attack human cells. Some of these are used to treat can­cer. They are selectively toxic mostly because they only damage cells that are in the process of dividing.

Antibiotics are sometimes called "wonder drugs" because they can cure many diseases that once were often fatal. The number of deaths that are caused by meningitis, pneumonia, and scarlet fever has de­clined drastically since people began using antibiotics.

Antibiotics are also used to treat infectious diseases in animals and to control bacteria and fungi that damage fruits and grains. Farmers sometimes add small amounts of antibiotics to livestock feed to stimu­late the animals’ growth.

Exercise 9. Answer the questions:

1. What may antibiotics be produced by?

2. What are antibiotic sub­stances obtained from?

3. What diseases may antibiotics be used in?

4. What cells are many antibiotics normally harmful?

5. When may antibiotics be selectively toxic?

6. Why do we call some antibiotics as "wonder drugs"?

7. Why was the number of deaths caused by meningitis, pneumonia, and scarlet fever de­clined drastically?

8. Where may antibiotics be also used to treat infectious diseases?

9. Why do farmers sometimes add small amounts of antibiotics to livestock feed?

10. What are the most frequent side-effects of antibiotics?