馈线室外部分的外防护层应有不少于（）点的外保护层接地连接。
A.1
B.2
C.3
D.4
参考答案：C
a+a+a=a3．______．
补全对话。
A: Hi, Li Lei! 1 What have you beer doing these days?
B: I have been a member of the school volunteer project. 2
A. Of course. But I don't know what I can do?
B: 3
A: Playing the guitar.
B: 4
A: 5 Thank you.
B: You are welcome.
A. Would you like to join us?
B. I haven't seen you for a long time.
C. Good idea.
D. What's your hobby?
E. Well, you could help coach a guitar team for little kids.
