单项选择题
What is normally used to pass a mooring line to a dock（）.
A.Distance line B.Gantline C.Heaving line D.Tag line
单项选择题 What is meant by the term two-blocked（）.
单项选择题 The use of（）between bags may lead to chafe and tearing of the bags.
单项选择题 The tackle that raises and lowers the boom is（）.
