单项选择题
A.Hoist rope is not kinked
B.Multiple part lines are not twisted around each other
C.The hook is centrally located over the load
D.All of the above
单项选择题 Before operating a non-oceangoing ship greater than 100 gross tons it must have a fixed piping system to discharge oily mixtures ashore. This system must include（）.
单项选择题 An instrument useful in predicting fog is the（）.
单项选择题 An advantage of nylon rope over manila rope is that nylon rope（）.