All VHF marine band radios operate in the simplex mode，which means that（）.

A mark or place at which a vessel comes under obligatory entry，transit，or escort procedure is know as（）.

How（）the cargo at loading port?

The weather is often（）in a high-pressure area.

There is a VHF set（）the front of the wheelhouse.

If you know that the vessel you are about to call on the VHF radio maintains a radio watch on both the working and the calling frequencies，which frequency should you call on? （）

The control of distress traffic is the responsibility of（）.

There is a（）mine in position 50°N，30°W.

Please（）all the lines fore and aft，the vessel is just in her position of the berth now.

I have been instructed that on my voyage（），I shall call at Maderra to pick up some cargo.