单项选择题
The quartermasters（）steer the ship and help the officer keep lookout.
A.duty B.on duty C.at duty D.in duty
单项选择题 The captain is in（）command of the ship.
单项选择题 The officer of the watch（）a good lookout on the bridge.
单项选择题 In the afternoon he often removes rust or（）some paint work.
