单项选择题
A vessel showing a rigid replica of the International Code flag “A” is engaged in（）.
A.diving operations B.dredging C.fishing D.mineclearance operations
单项选择题 A vessel showing a green light over a white light in a vertical line above the level of the sidelights is（）.
单项选择题 A vessel servicing a pipeline during the day shall display（）.
单项选择题 A vessel sailing shall keep out of the way of all of the following vessels except a vessel （）.
