单项选择题
Waste oil from the lube oil sumps of machinery may NOT be （）.
A.drained into the vessels bilges B.reclaimed for other uses C.held in a slop tank D.purified and then reused
单项选择题 Portable carbon dioxide fire extinguishers should be sent ashore to be recharged （）.
单项选择题 The lengthening of a crack formed in the shell plating of a ship may be prevented by （）.
单项选择题 The fire extinguishing action of CO2 comes mostly from （）.
