单项选择题
A.vomiting
B.blue color and lack of breathing
C.irregular breathing
D.unconsciousness
单项选择题 Seawater may be used for drinking（）.
单项选择题 Once you have established the daily ration of drinking water in a survival situation，how should you drink it?（）
单项选择题 On an oceangoing vessel，for each person a lifeboat (without desalting kits) is certified to carry，the boat must be supplied with（）.