问题 选择题

儿童的骨柔韧有弹性、不易骨折,但易变形,原因是骨成分的含量 (  )

A.有机物约为2/3,无机物约为1/3  

B.有机物约为1/3,无机物约为2/3

C.有机物多于1/3,无机物少于2/3

D.有机物少于1/3,无机物多于2/3

答案

答案:C

题目分析: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

阅读理解
Stress(压力) is everywhere in our everyday life. Not only men have it, but also women and young people. 
The most important reasons of stress are: diseases, exams, making money, getting married, moving houses, changing jobs, ending friendships and so on.
How do you know whether you have stress? Give your answers to the following questions?
 
 
Yes
No
1
Do you easily get angry?
 
 
2
Do you often sleep badly?
 
 
3
Do you get headaches a lot?
 
 
4
Do you take sleeping pills (药片)?
 
 
5
Do you find it difficult to relax?
 
 
6
Do you usually hide your feelings?
 
 
7
Do you smoke and drink a lot to keep quiet?
 
 
8
Do you find it difficult to put your heart into something?
 
 
If you answer “Yes” to more than two of these questions, you are one of those people with stress. So what can you do about it?
Doing relaxing exercises, talking with friends and listening to light music are all usual ways of relieving(减轻) stress. However, doctors now say that there are easier ways --- people should laugh and smile more often. When you laugh and smile, your body relaxes. They also say that people, especially men, should cry more often, be­cause crying is the natural way of relieving stress. 
小题1:If you have over ________ problems listed in the table, you are the person with stress.
A.twoB.threeC.fourD.eight
小题2:Which of the followings is NOT the reason of stress?
A.Taking exams.B.Watching films.
C.Making money.D.Moving houses.
小题3:What’s the easier way to relax your body?
A.Talking with friends.B.Doing relaxing exercises.
C.Laughing, smiling and crying.D.Listening to light music.
小题4:The main idea of the passage is           .
A.about stress and how to relieve your stress
B.that there are many reasons for having stress
C.that laughing and smiling more can help relieve your stress
D.stress is everywhere in our everyday life
多项选择题