单项选择题
A.Secure all lighting to the main deck
B.Provide a portable fan to blow away fumes
C.Prohibit smoking in the area
D.Display a black triangle during daylight hours
单项选择题 Before the seas get rough, it is a good safety practice to （）.
单项选择题 Which of the fire extinguishers listed is to be weighed annually and sent ashore for recharging if the weight loss exceeds 10% of the weight of a full charge?（）
单项选择题 A carbon dioxide fire extinguisher has been partially discharged, and should be immediately （）.