问题 选择题

儿童少年期的骨,硬度小、柔韧而弹性大,这是因为骨中(  )

A.无机物超过2/3

B.无机物不到1/3

C.有机物超过1/3

D.有机物不到1/3

答案

骨的成分包括有机物和无机物,有机物越多,骨的柔韧性越强,无机物越多,骨的硬度越大;在不同时期,骨的成分不同,如下表:

所以在儿童青少年的骨中,有机物多于1/3,骨的弹性大,容易变形,所以青少年要注意坐、立、行的姿势.

故选:C

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根据短文内容,回答下列问题。

     Nowadays more and more people in the world are getting fatter, which troubles them a lot. In the past 25

years, the number of the people with obesity (肥胖症) in Europe has doubled. Experts say that it has a lot to

do with our eating habits.

     Our eating habits are very important for good health and a strong body. Most of us like eating sweets and

ice cream better than meat and rice. Sweets and ice cream are not bad for us if we eat them at the end of a

meal. If we eat them before a meal, they may take away our appetite (食欲).

     It's important for us to eat our meal at the same time each day. When we feel worried or excited, we may

not want to eat. A long time ago, in England, some judges often decided whether a man was tell-ing the truth

by giving him some dry bread. If the man could not swallow (呑) the bread, it meant that he wasn't telling the

truth. A man who is worrying something has difficulty in swallowing anything dry, because he loses his appetite.

1. Are more and more people getting fatter in the world?

    ________________________________________________________________

2. Do most people like eating sweets or meat?

    ________________________________________________________________

3. What may happen to people when they feel worried or excited? 

    ________________________________________________________________

4. Why did the judges give some dry bread to the man in old England? 

    ________________________________________________________________

5. What are good eating habits? 

    ________________________________________________________________

单项选择题