单项选择题
The second engineer seemed to know what the sign （）.
A.stand by B.stand for C.stood by D.stood for
单项选择题 We have just repaired the motorRemember （） to it during your watch.
单项选择题 Rounds （）Everything is in good order.
单项选择题 Tell the engineer on duty to keep close watch over the machine （）temperature is sometimes a bit too high.
