单项选择题
The sailors are （）the leakage in fire-fighting and life-saving operations.
A. blocking up B. looking up C. looking out D. taking up
单项选择题 The （）from waterline to the bottom of the ship is called draft.
单项选择题 The （）part of the ship on port is called the port bow.
单项选择题 Because of the （）, we have to keep a sharp lookout.
