题目内容：
It was a holiday weekend. The police officers were21in a hot room receiving instructionsfrom their captain. One of these officers was Ed. Williams. He and the other officers were on22 duty because they knew that over the weekend two weeks23over 4O0 people had died fromaccidents caused by24drivers. Over 4, 000 people had25serious injuries ( 受伤), allcaused by such drivers. The officers would try their best to26 such accidents before theyhappened. Joe Forest was enjoying27at a family party. It was getting late and Joe told his sister thathe was28. Joe's sister asked him to stay and wait a few hours29he drove,"Don't worry.
I'm going to be fine. I'm going to drive30. I only had a few drinks,"Joe said.
Officer Williams was at his31watching the passing cars. A green car was coming,32
from left to right. Officer Williams stopped the car and told Joe to get out. He asked Joe to33 along the white line. Joe couldn't do it. Joe also34the breath test. Officer Williams told Joe thathe must appear in court the next week and he35drive his car home. Joe called his sister. Hissister came and drove him home.
That was Joe's first offence(违章). He appeared in court and received a $ 400 fine(罚款). Hewas not allowed to drive for sixty days. Other drivers were lucky for Joe didn't kill them. But whatabout the future, was Joe going to stop drinking and driving?
根据以上内容,回答题.
第21答案是（ ） A．waiting
B．talking
C．seated
D．searching
参考答案：
答案解析：