埋设于地下有防腐要求的给水管道应在（）进行隐蔽工程检查（验收）。
A、管道安装后；
B、防腐处理之前；
C、封闭之前；
D、封闭之后.
参考答案：B
根据中文提示，用词组的适当形式填空。每空一词。
1. — Would you mind ________ (关掉) the radio?
— Of course not. I'll do it at once.
2. Li Lei is ________ (擅长) playing chess.
3. It's cold outside. You'd better________ (穿上) your coat.
4. I ________ (等候) you at the school gate, but you didn't come.
5. There are many wild animals ________ (处于危险中), such as pandas and tigers.
世界上最大的宫殿建筑群是（）。
A、故宫
B、克里姆林宫
