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? （）

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

I’d like to know something about the cargo condition at the loading port（）detail.

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

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

How should the letter O be pronounced when spoken on the radiotelephone?（）

The present voyage of my ship began at the port of Shanghai after loading 8 000 tons of Cargo on board and ended after discharging the Cargo at the port of Hong Kong，which was（）.

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

The expression STAND-BY ENGINE means:（）.

A call between any two ship stations on an intership working frequency shall have a maximum duration of（）.