Reading passages

316- We can understand from the passage that the protection supplied by serum injection ------- .
A) should only be thought of in exceptional conditions
B) is immediately effective but short-termed
C) is unreliable and can have an adverse effect on the patient
D) has generally proved unsuccessful except for during diphtheria epidemics
E) lasts long and is entirely safe
317- The text gives a detailed account of ------- .
A) how to determine who are vulnerable in an outbreak of diphtheria
B) the special advantages of active prophylactic immunisation
C) an immunisation scheme specially designed to deal with an outbreak of diphtheria in a school
D) the stages through which diphtheria turns out an epidemic
E) the various symptoms of diphtheria and the treatment called for at different stages of the disease
318- The writer maintains that, in an outbreak of diphtheria in a school, it is wise to keep carriers away from the other children ------- .
A) even if there are very few of them
B) since this will make the treatment more effective
C) even it this means closing the school
D) otherwise they will all become re-infected
E) especially in the period just before active immunity takes place
Worms are known as intestinal parasites, but the only common types found in France are thread worms, the tiny thread-like worms which cause irritability and itching in the skin of children, less often in adults. Then there are round-worms, somewhat resembling the ordinary garden earthworm, which seldom lead to symptoms. Finally, the third group is the tapeworms which my reach a length of 6 m. Many parasitic worms lead a double life, they spend part of their life in the human intestine and the other part in the muscles of another animal. The tapeworm, for example, while in the human intestine, lays eggs which pass out of the body in the excrete, and are then swallowed by various animals, especially in those parts of the world where human excrete are used as fertilisers in the fields.