单项选择题
As a duty sailor, he should （）.
A. keep a gangway watch B. often look around the ship C. hoist and lower national flag on time D. A+B+C
单项选择题 The gangway is one meter higher,（） it, please.
单项选择题 The gangway is one meter lower, （）it please.
单项选择题 （）the gangway, please.
