单项选择题
A. loading cargo B. arrival in port C. departure from port D. unloading cargo
National flag should not be （）up.A.rollingB.rollsC.roll...
单项选择题National flag should not be （）up.
A.rolling B.rolls C.rolled D.roll
You should keep national flag（）.A.flyingB.flewC.flownD....
单项选择题You should keep national flag（）.
A.flying B.flew C.flown D.flies
You should slack the mooring lines （）when the wind is b...
单项选择题You should slack the mooring lines （）when the wind is big.
A. at the same time B. on time C. in time D. at times
