单项选择题
During fueling，all doors，hatches，and ports（）.
A.to windward should be opened and the ones to leeward should be closed B.to leeward should be opened and the ones to windward should be closed C.should be opened D.should be closed
单项选择题 Cracks may be prevented from developing at the corners of welded plating inserts by（）.
单项选择题 Connecting elements of a mooring system should be fabricated from（）.
单项选择题 Chain slings are suitable for heavy slender articles，such as（）.
