单项选择题
There is actually an overlapped area of（）ocean regions somewhere in Western European waters.
A.two B.three C.more than two D.more than three
单项选择题 The INMARSAT system has five major components, they are:（）
单项选择题 The INMARSAT consists of（）major components.
单项选择题 Why should the SES operators be very careful when the ship enters the area where three ocean regions overlap? Because（）.
