单项选择题
We must （）to inspect the problems about the safety of fire prevention.
A.prepares B.preparing C.prepared D.prepare
单项选择题 When you keep a gangway watch, you should （）the mooring lines according to the rise and fall of the tide.
单项选择题 Lower gangway into place and （）safety net.
单项选择题 We should hoist national flag （）.
