单项选择题
The vessel was drifted off from her（）due to strong wind.
A.course B.track C.direction D.trend
单项选择题 The use of the danger signal（）.
单项选择题 The two main types of load cells used in mooring tension gauges are（）.
单项选择题 The transmission of messages respecting the dangers specified is free（）cost to the ships concerned.
