A tide is called diurnal when（）.

The circulation around a low pressure center in the Northern Hemisphere is（）.

When the wave period and the apparent rolling period are the same（）.

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

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

Manoeuvring information can not be obtained from（）.

Shipboard Emergency Drills must be carried out at least（）on board cargo ship.

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

The ISM code is part of（）.

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