One day, a teacher was giving a speech to his students .He held up（举起）a glass of water and

One day, a teacher was giving a speech to his students .He held up（举起）a glass of water and asked the class. How heavy do you think this glass of water is ?
The students’ answers ranged（范围） from 20g to 500g .
It does not matter on the weight itself .It depends on how long you hold it .If I hold it for a minute ,it is OK. If I hold it for an hour ,I will have an ache in my right arm .If I hold it for a day ,you will have to call an ambulance（救护车）.It is exactly the same weight ,but the longer I hold it ,the heavier it bees.
If we carry our burdens （负担）all the time, sooner or later ,we will not be able to carry on ,the burden being increasingly heavier .
What you have to do is to put the glass down ,rest for a while before holding it up again .
We have to put down the burden sometimes ,so that we can be refreshed and are able to carry on .
So before you return home from work tonight ,put the burden of work down .Don’t carry it back home. You can pick it up tomorrow .
Whatever burdens you are having now on your shoulders, let it down for a moment if you can .
【小题1】The teacher brought a glass of water to the class because     
A. he was very thirsty  B. his arms were strong  C. it was a good example
【小题2】A glass of water in this passage referred to （指）    
A. knowledge  B. the burden  C .the time
【小题3】Accordign to the teacher ,you may feel     if you put down the burden sometimes.
A. more energetic  B. much heavier  C. more stressed out （压力、紧张）
【小题4】This was a lesson about    
A. how to relax oneself in life  B. how to solve a physics problem .
C. how to keep fit by drinking water
【小题5】Which of the following statements is TRUE according to the passage ?
A .You could bee heavier and heavier if you held a glass of water in your hand .
B. All the students in the class knew what the weight of the glass of water exactly was
C. The teacher had a good way of making his lesson clear and easy to be understood C