单项选择题
Aboard a survival craft,ether can be used to（）.
A.start the engine in cold weather B.aid in helping personnel breathe C.prime the sprinkler system D.prime the air supply
单项选择题 Above-normal tides near the center of a hurricane maybe caused by the（）.
单项选择题 According to the customs of this port, the work of opening and closing hatch covers is done by（）.
单项选择题 Advise（）your fishing gear.
