21. The reason why people might not be able to stay alive in a world

without emotion is that______.

 A. they would not be able to tell the texture of objects

 B. they would not know what was harmful to them

 C. they would not be happy with a life without love

 D. they would do things that hurt each other’s feelings

22. According to the passage, people’s learning activities are

possible because they______.

 A. believe that emotions are fundamental

 B. benefit from providing help to one another

 C. enjoy being rewarded for doing the right thing

 D. know what is vital to the progress of society

23. It can be inferred from the passage that the economic foundation of

society is dependent on______.

 A. the ability to make money       B. the will to work for pleasure

 C. the capacity to enjoy incentives   D. the wish to create more

products