单项选择题
A.tie themselves to the unit so they won't drift with the current
B.form a small circular group to create a warmer pocket of water in the center of the circle
C.send the strongest swimmer to shore for assistance
D.form a raft by lashing their life preservers together
单项选择题 If the named port is one at which no tugs are ever obtainable，and the chartered vessel can not，by reason of her size，reach that port without the assistance of tugs，the port is（）.
单项选择题 If it is impossible to avoid a hurricane in the Northern Hemisphere，the most favorable place to be when the storm passes is in（）.
单项选择题 Following a collision or accident，the Master of each vessel involved must render assistance to persons affected by the collision or accident（）.