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? （）

There is a drifting mine（）in position 21 degrees 31 minutes North 124 degrees 20 minutes East.

The generators on your rig have shut down，leaving you without navigation lights. Which emergency signal would you transmit over the VHF radio to alert vessels in the area of your predicament? （）

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

（）your present speed?

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

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

（），you can’t finish discharging tomorrow!

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

One hour before arrival at Elbe 1 light vessel，masters are advised to contact the pilot boat by（）.