单项选择题
Send a fire （）(火势探测员) to see the situation .
A.detect B.detector C.watch D.inspector
单项选择题 Close the port side （）(通风口) .
单项选择题 The emergency alarm is sounded on （）(汽笛) according to master’s order.
单项选择题 There is a smell of gas in the hold. You must wear your （）(氧气面罩).
