单项选择题
A. in case B. case of C. in case of D. in the case of
Fire and boat drills are carried out （）.A.periodicallyB...
单项选择题Fire and boat drills are carried out （）.
A.periodically B.quarterly C.monthly D.yearly
All the crew must know the locations as well as the （）o...
单项选择题All the crew must know the locations as well as the （）of the life-saving and fire-fighting appliances.
A.operate B.operating C.operations D.operated
What kind of （）can be used for gas and chemical fires?A...
单项选择题What kind of （）can be used for gas and chemical fires?
A.equipment B.apparatus C.extinguishers D.machines
