三相6脉冲管电压脉动率是 A．3.4% B．7.2% C．13.4% D．20% E

情景交际（10分）从方框中选择适当的句子补全对话，其中有两项是多余的。
A: Hello .Nice to meet you . .
B: Nice to meet you , too .
A: 小题1:_______  .
B:  I went to the Palace Museum and the Great Wall .
A:  Really ?小题2:________
B:  Yes , I did . It was very great.
A:  but the weather was not good , was it ?
B:  Yes .小题3:_______ .
A: How were the people in Beijing ?
B: 小题4:________  .
A :小题5:________

A. How great ! I hope I can go there one day.              B. It was hot and humid. C. I went there by plane.       D. Did you go to Tian' anmen Square ?. E. They were friendly to foreigners and they always helped us .              F. Did you go there with your parents? G. Where did you go on holiday ?