单项选择题
The two main types of load cells used in mooring tension gauges are（）.
A.distortion and compression B.hydraulic and mechanical C.magnetic and applied torque D.frictionless and hydraulic
单项选择题 The transmission of messages respecting the dangers specified is free（）cost to the ships concerned.
单项选择题 The towing light is a(n)（）.
单项选择题 The term OIL as used in the Oil Pollution Regulations means（）.
