单项选择题
Sailing vessels are stand-on over power-driven vessels except（）.
A.in a crossing situation B.in a meeting situation C.when they are the overtaking vessel D.on the inland waters of the PR China
单项选择题 Set of current is（）.
单项选择题 Several shoals（）reported to exist in the area south-west of the Brothers.
单项选择题 A system of cleaning the tanks by washing them with the cargo of crude oil while it is being discharged is known as（）.
