题目内容：

Happiness is like a pebble(鹅卵石)____ into a pool to bring ____ ever-widening circle of ripples（波纹）. As Stevenson has said, being happy is a duty.

There ____ no exact definition of the word happiness. Happy people are happy ____ all sorts of reasons. The key is not wealth or physical health, since we find beggars, invalids(伤残者) and so-called failures, ___ are extremely happy.

Being happy is a sort of unexpected dividend收益. But ____ happy is a total triumph(胜利) of soul and character. It is not selfish to work hard for it. It is, indeed, a duty to ourselves and others.

Being __ is like an infectious illness.__ causes people to shrink away from the sufferer. He soon ____ himself alone, sad and frustrated. There is, however, a cure so simple; if you don’t feel happy, pretend to be!

It works. __you will find that instead of driving people away, you attract them. You discover how deeply rewarding（有益的）it is to be the ____ of wider and wider circles of good will.

Then the make-believe becomes a ___. You own the peace of mind, and can forget yourself in being of service to ____.

Being happy, once(一旦) it is realized as a duty and started as a ____, opens doors into unimaginable gardens crowded___ grateful friends.

1.A.dropB. droppingC. to dropD. dropped

2.A. aB. anC. theD. /

3.A. beB. areC. isD. was

4.A.becauseB. forC. asD. since

5.A.whichB. whoC. thatD. whom

6.A. lookB. stayingC. to feelD. being

7.A.happyB. braveC. confidentD. unhappy

8.A.ItB. WhichC. ThatD. What

9.A.enjoysB. makesC. findsD. lets

10.A. Long beforeB. after longC. Before longD. Long ago

11.A. centerB. topC. middleD. end

12.A.realB. realityC. reallyD. realize

13.A. anotherB. othersC. elseD. other

14.A. surpriseB. pleasureC. hobbyD. habit

15.A.inB. toC. withD. of