Bales close to the deckhead should be covered to prevent（）.

When steering by autopilot,how often should the steering be checked?（）

Fog is likely to occur when there is little difference between the dew point and the（）.

It is dangerous for vessels without the operational radar（）the estuary.

Before any loading takes place any signs of the previous cargo should do（）.

Full details of all lights and fog signals are shown on（）.

Despite the rising importance and great convenience of the gyrocompass,the magnetic compass still retain its importance because of its（）.

How long are you prohibited to consume alcohol prior to serving as a member of a watch?（）

The dew point temperature is（）.

Which of the following is not an operation mode of AIS?（）