单项选择题
A vessel may be unable to take proper and effective action due to the speed（）too high or，in some circumstances，too low.
A.is B.is to be C.will be D.being
单项选择题 A tourniquet should be used to control bleeding ONLY（）.
单项选择题 Preventer bars are fitted on lifeboat releasing hooks to prevent（）.
单项选择题 The control lever for the mechanical disengaging apparatus in a lifeboat shall（）.
