单项选择题
Small hull leaks can be temporarily repaired by（）.
A.parcelling B.parbuckling C.caulking D.seizing
单项选择题 Rivets are usually made of（）.
单项选择题 Repairing damage to the hull at or above the waterline reduces the threat of（）.
单项选择题 Repair of structures on a ship in the vicinity of liquid mud handling areas presents what possible hazard?（）
