单项选择题
The burden of proving unseaworthiness is upon those who（）it.
A.approves B.alleges C.allows D.permits
单项选择题 The bottom of the mast rests on a part of the keel called the mast（）.
单项选择题 The boom stops are installed on an offshore crane to（）.
单项选择题 The annual survey for endorsement of a Load Line Certificate must be held within（）.
