Put the（）（防鼠挡）on the lines.

单项选择题National flag should not be（卷叠）（）.

A. rolling up
B. rolls up
C. rolled up
D. roll up

单项选择题We shall prepare for(港口国)（）inspection.

A.PSC
B.ARPA
C.GPS
D.ECDIS

单项选择题（）（降）the flag.

A.Hoist
B.Top
C.Lower
D.Bring

单项选择题You should keep national flag（飘扬）（）.

A.flew
B.flown
C.flying
D.flies

单项选择题（）（调整）ropes when necessary.

A.Try
B.Adjust
C.Notice
D.Operate