题目：
Vessels are required（）Singapore Port Service when passing the points indicated.
A.communicating with
B.to communicate with
C.be communicated
D.will communicate
答案：
参考答案：B
Vessels are required（）Singapore Port Service when passing the points indicated.
A.communicating with
B.to communicate with
C.be communicated
D.will communicate
参考答案：B
