根据句意及首字母提示补全单词。

1. China has a p_____ of about 1.3 billion.

2. The bad air makes my chest hurt and it's difficult for me to b_____.

3. A_____ we have built the Green Great Wall, we still need to work hard to protect the environment.

4. W_____ you go there, please telephone me. I'll go with you.

5. There's no d_____ that computers are widely used by workers.

关于版本获取，正确的是（）。

A.以在版本管理系统中凭密码下载为主

B.必要性可采取FTP和光盘传送方式

C.禁止未经申请从非正常渠道获取

D.从研发处获取