A. INTO B. FROM C. UNDER D. TO READ THE FOLLOWING PASSAGE AN...

Câu 42: A. into B. from C. under D. to

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the

correct answer to each of the following questions from 43 to 52.

The principle of use and disuse states that those parts of organisms' bodies that are used grown

larger. Those parts that are not tend to wither away. It is an observed fact that when you exercise

particular muscles, they grow. Those that are never used dimish. By examining a man's body, we can tell

which muscles he uses and which he doesn't. We may even be able to guess his profession or his reaction.

Enthusiasts of the "body- building" cult make use of the principle of use and disuse to "build" their

bodies, almost like a piece of sculpture, into whatever unnatural shape is demanded by fashion in this

peculiar minority culture. Muscles are not the only parts of the body that respond to use in this kind of

way. Walk barefoot and you acquire harder skin on your soles. It is easy to tell a farmer from a bank teller

by looking at their hands alone. The farmer's hands are horny, hardened by long exposure to rough work.

The teller's hands are relatively soft.

The principle of use and disuse enables animals to become better at the job of surviving in their

world, progressively better during their lifetime as a result of living in that world. Humans, through direct

exposure to sunlight, or lack of it, develop a skin color which equips them better to survive in the

particular local conditions.

Too much sunlight is dangerous. Enthusiastic sunbathers with very fair skins are susceptible to

skin cancer. Too little sunlight, on the other hand, leads to vitamin-D deficiency and rickets. The brown

pigment melanin which is synthesized under the influence of sunlight, makes a screen to protect the

underlying tissues from the harmful effects of further sunlight. If a suntanned person moves to a less

sunny climate, the melanin disappears, and the body is able to benefit from what little sun there is. This

can be represented as an instance of the principle of use and disuse: skin goes brown when it is "used",

and fades to white when it is not.