问题 选择题

调节人体生长发育,缺少会患侏儒症的激素是(  )

A.生长激素

B.甲状腺激素

C.胸腺激素

D.胰岛素

答案

生长激素是由垂体分泌的,有调节人体生长发育的作用.如果幼年时生长激素分泌不足,则生长迟缓,身材矮小,到了成年,有的身高才只有70cm,但是智力一般是正常的,这叫侏儒症;如果幼年时期生长激素分泌过多,则会过分生长,到了成年,有的身高可达2.6m以上,这叫巨人症;如果成年人的生长激素分泌过多,就会引起短骨的生长,造成手掌大、手指粗、鼻高、下颌前突等症状,这叫肢端肥大症.

故选:A

阅读理解

In the United States, 30 percent of the people have a “weight problem”. To many people the cause is obvious (明显的): they eat too much. But scientific evidence (证据) does little to support this idea. Going back to America of 1910, we find that people were thinner than today, yet they ate more food. In those days people worked harder physically, walked more, used machines much less, and didn’t watch television.

Several modern studies, moreover, have shown that fatter people don’t eat more on average than thinner people. A 1979 study of 3,545 London office workers showed that fat people eat less than slim (苗条的) people.

Studies also show that slim people are more active than fat people. A study by a research group at Stanford University found the following interesting facts:

The more the man ran, the greater loss of the body fat.

The more they ran, the greater increase in food intake.

Thus, those who ran the most ate the most, yet lost the greatest amount of body fat.

小题1: Nowadays many Americans have the problem that ______.

A.they are too slim

B.they work too hard

C.they are too fat

D.they lose too much body fat小题2: According to the passage, how many people in 900 Americans have a “weight problem”?

A.150.

B.300.

C.600.

D.270.小题3:Is there any scientific evidence to support the idea that eating too much is the cause of a “weight problem”?

A.Yes, there is plenty of evidence.

B.Of course, there is some evidence to support this.

C.There is hardly any scientific evidence to support this.

D.We are not sure.小题4:The Americans in 1910 ________.

A.ate more food and had more physical activities

B.ate less food but had more physical activities

C.ate less food and had less physical activities

D.had more problems

单项选择题