单项选择题
A.common B.oil C.electrical D.chemical
Lifeboat launching is operated at intervals of （）months...
单项选择题Lifeboat launching is operated at intervals of （）months.
A.one B.two C.three D.four
Fire drill is carried out once a （）.A.yearB.dayC.weekD....
单项选择题Fire drill is carried out once a （）.
A.year B.day C.week D.month
Any emergency pump situated （）machinery space should al...
单项选择题Any emergency pump situated （）machinery space should also be started.
A.outside B.under C.beside D.besides
