阅读下面短文，从短文后所给各题的四个选项中选出能填入空白处的最佳选项。
Many years ago, whites ruled South Africa. Apartheid（种族隔离制度）was the   16   of the land. One evening, two middle-aged blacks met in a “whites only” section of Johannesburg. One of them had a permit to work in the area, the other did not, which   17   he could be put behind bars（关押）for staying in this zone.   18   they saw a policeman coming towards them, and   19  .
“Run!” whispered the man with the permit to his friend, “I’ll   20  .” They started running and the policeman began chasing them, shouting “stop, stop”. Finally he caught the second man.
“Did you think you could outrun me!” he snarled. “Show me your   21  ！”
The man, playing for time, began reaching in his pocket and finally took out his permit. The policeman was surprised and realized that he had been   22  . The man without the permit was now too far away to be caught.
“When you had a permit why did you run!” he shouted   23  .
“Doctor’s   24  ,” said the man. “He has asked me to run a mile every evening.”
“Oh, yes? ” Sneered the policeman. “Then why was your friend   25  ?”
“His doctor has also ordered him to run,” said the man.
The policeman became   26   with anger. “You think you’re very   27  , don’t you?” he snarled. “But tell me, if you were running   28   for your health why didn’t you stop when you saw me running after you? And don’t tell me you didn’t see me chasing you. I know you did!”
“Of course I   29   you were running after me,” said the man.
“Then why didn’t you stop?” asked the policeman.
“It was   30  of me,” said the man, “but I thought you too had been ordered to run by your doctor.”

A．property B．mistake C．law D．custom

A．meant B．showed C．replied D．imagined

A．Happily B．Suddenly C．Finally D．Generally

A．hid B．fell C．cried D．froze

A．fight B．explain C．follow D．walk

A．invitation B．permit C．pocket D．ticket

A．fooled B．hurt C．blamed D．abandoned

A．nervously B．sadly C．carefully D．angrily

A．attitudes B．methods C．orders D．hopes

A．stopping B．missing C．staying D．running

A．shy B．strict C．red D．serious

A．brave B．healthy C．native D．smart

A．only B．also C．never D．often

A．remembered B．knew C．believed D．agreed

A．stupid B．rude C．kind D．wise