阅读短文，选择正确答案。
Take three basins (盆). Fill the first basin with water which is as hot as you are able to bear (承受) with your
hands. In the second basin mix hot water with cold water. Fill the third basin with cold water from the tap
(水龙头).
Now place the basins on the table. Put your right hand in the hot water. Put your left hand in the cold water.
You will find that your right hand feels hot and your left hand feels cold. After twenty seconds move both your
hands in the lukewarm (微温的) water. What do you feel? Your left hand feels warm and your right hand feels
cold. But both hands are in the same basin of water.
1. The writer is talking about _______. [ ]
A. hot water
B. cold water
C. basins
D. an experiment
2. How many basins are needed in the experiment? [ ]
A. One
B. Two
C. Three
D. Four
3. Your left hand feels warm and your right hand feels cold because _______. [ ]
A. they are in the same basin of water
B. your right hand is stronger than your left hand
C. your left hand is stronger than your right hand
D. they were in different basins of water a short time ago
4. After putting your hand in the cold water, you put it in the hot water. You will find ______. [ ]
A. the water too hot for you to bear
B. the hot water feels lukewarm
C. the water feels cold
D. your hand turns black
5. This experiment shows that _______. [ ]
A. sometimes our senses deceive (欺骗) us
B. we can always get to know whether something is hot or cold by feeling it with our hands
C. hot water and cold water do not mix
D. one of our hands is stronger than the other
，|b|=1，则|a+b|=（）。