单项选择题
A.operate B.operation C.co-operate D.co-operation
The signals that will be used for emergency should be c...
单项选择题The signals that will be used for emergency should be clearly （）.
A. set out B. set off C. get off D. cut off
The fire drill is （）. You are dismissed.A.finishB.finis...
单项选择题The fire drill is （）. You are dismissed.
A.finish B.finished C.begin D.beginning
Lower the （）ladder.A.embarkB.embarkationC.disembarkD.B+...
单项选择题Lower the （）ladder.
A.embark B.embarkation C.disembark D.B+C
