单项选择题
Fire and boat drills are carried out （）.
A.periodically B.quarterly C.monthly D.yearly
单项选择题 All the crew must know the locations as well as the （）of the life-saving and fire-fighting appliances.
单项选择题 What kind of （）can be used for gas and chemical fires?
单项选择题 Fires can be divided into different （）.
