单项选择题
What kind of （）can be used for gas and chemical fires?
A.equipment B.apparatus C.extinguishers D.machines
单项选择题 Fires can be divided into different （）.
单项选择题 We are loading dangerous cargo, no （）, please.
单项选择题 If there is a fire on board, inform the bridge and give the （）at once.
