单项选择题 How is the Master or operator of a vessel required to keep the crew informed of the regulations concerning the discharging of garbage overboard?（）.

单项选择题 Biodegradation of the oil slick in sea water is assisted by all the following marine micro-organisms which are capable of metabolising oil compounds except（）.

单项选择题 Before operating a non-oceangoing ship greater than 100 gross tons it must have a fixed piping system to discharge oily mixtures ashore. This system must include（）.