单项选择题
A.shorter than the rowing oars
B.the same length as the rowing oars
C.longer than the rowing oars
D.unrelated to the length of the rowing oars
单项选择题 The grab rail of a metal lifeboat is normally located（）.
单项选择题 The governor brake shall be capable of controlling the speed of lowering a fully equipped lifeboat with its complement of persons on board at（）.
单项选择题 The first treatment given to a person overcome by benzene vapor should be to（）.