单项选择题
A.the man has been missing for a period of time
B.the sea water is very cold and the man is visible
C.there is thick fog
D.the wind was from astern on the original course
单项选择题 A person with diabetes has received a minor leg injured. The symptoms of the onset of a diabetic coma include（）.
单项选择题 A person who gets battery acid in an eye should IMMEDIATELY wash the eye with（）.
单项选择题 A person may operate an air compressor in which of the following areas on board a tank barge?（）