单项选择题
A.be safe if mixed with fresh water
B.prevent seasickness
C.promote urine excretion
D.protect against heat cramps
单项选择题 Immediately after abandoning a vessel, lookouts should be posted aboard liferafts to look for（）
单项选择题 When administering artificial respiration to an adult, the breathing cycle should be repeated about （）
单项选择题 When administering artificial respiration, it is of the utmost important to （）