用所给词的适当形式填空。

1. They hope _____ (visit) China again.

2. We won't begin the meeting until he _____ (come).

3. I had some problems _____ (work) out the math problem.

4. Thanks a lot for _____ (invite) me to your birthday party.

5. Did you watch those boys _____ (play) soccer yesterday afternoon?

下列关于我国工业生产分布的说法，正确的是[ ]

A．轻纺工业由内地向沿海扩展  

B．工业分布由山区向平原扩展  

C．新中国成立前，重工业集中在辽中南  

D．新中国成立后，工作重心是在内地建设新工业基地和工业中心