单项选择题
A.without losing the rhythm of respiration
B.only with the help of two other people
C.by not stopping the respiration for more than 5 minutes
D.at ten-minute intervals
单项选择题 Before personnel are lifted from a vessel in a personnel basket，the vessel should be（）.
单项选择题 After the boat is at the top of the davit heads，the davit arms begin moving up the tracks and are stopped by the（）.
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.