Indefinite

2. Сравнительная характеристика неличных форм

глагола

1. Измените залог сказуемого в следующих предложениях:

a) The ribs are moved by a series of intercostal muscles.

b) The thorax is separated from the abdomen by the diaphragm.

c) Vibration of these cords produces sound waves.

d) The trachea divides into two bronchi.

e) The bronchi are also supported by cartilages.

f) Each lung is surrounded by the pleural cavity.

g) This is bounded by two membranes which secrete pleural fluid into the cavity.

h) The volume of the thorax is decreased.

2. Найдите в тексте Gaseous exchange in mammals примеры неличных форм глагола, сравните их грамматическую форму, функции в предложении, способы перевода.

Summary

Smoking

Tobacco is responsible for 15-20% of all deaths in Britain, amounting to about 100000 people every year. The three main diseases closely linked with smoking are:

Coronary heart disease

Smoking increases the likelihood of fatty deposits arising on the inner lining of the arteries (atherosclerosis), which cause the lumen to narrow, so restricting the movement of blood through them. Where this narrowing occurs in the coronary artery it can lead to a heart attack; narrowing in the carotid artery may result in a stroke.

Lung cancer

There is more than one type of lung cancer but bronchial carcinoma is by far the most common. The tars in tobacco smoke may induce the epithelial cells lining the bronchial tubes to become cancerous. If not treated, the tumour may completely disrupt the functioning of the lung, leaving surgical removal as the only effective treatment. A highly persistent cough, blood in the sputum and chest pains are all symptoms of lung cancer.

Chronic bronchitis

The tars in tobacco irritate the epithelial lining of the bronchial tubes causing it to produce excess mucus. The cilia lining the tubes become damaged and unable to remove this mucus in the usual manner. Only by coughing can the mucus be expelled and in time this leads to scarring and narrowing of the bronchial tubes, causing breathlessness. Other smoking-related conditions include emphysema; cancer of the mouth, throat, bladder and pancreas; other cardiovascular diseases; peptic ulcers; narrowing of blood vessels in limbs; damage to the unborn child.

Tobacco smoke is a mixture of chemicals, a number of which interact with each other, multiplying their effects. The three constituents which do most harm are nicotine, carbon monoxide and tars.

Nicotine:

• is quickly absorbed into the blood, reaching the brain in 30 seconds;

• causes the platelets to become sticky, leading to clotting;

• stimulates production of adrenaline, leading to increased heart rate and raised blood pressure, which puts an extra strain on the heart.

Carbon monoxide:

• lowers the oxygen-carrying capacity of the blood;

• may aggravate angina;

• slows the growth of the fetus.

Tars:

• form an aerosol of minute droplets which enter the respiratory system causing thickening of the epithelium and leading to chronic bronchitis;

• paralyse cilia, so dust, germs and mucus accumulate in the lungs, leading to infection and damage;

• contain carcinogens - heavy smokers have a 25% greater risk of cancer than non-smokers.

Translation