单项选择题
A.lower B.lowering C.lowered D.topped
We are going to carry out an emergency （）.A.practiseB.p...
单项选择题We are going to carry out an emergency （）.
A.practise B.practice C.drill D.drills
Throw a （）to the person overboard and help him come on ...
单项选择题Throw a （）to the person overboard and help him come on board.
A.lifeboat B.life-raft C.lifebuoy D.fire mask
（）extinguish oil and electrical fires with water.A.DoB....
单项选择题（）extinguish oil and electrical fires with water.
A.Do B.Did C.Never D.Isn’t
