Which of the following shall not the officers in charge of the navigational watch do?（）

Manoeuvring information can not be obtained from（）.

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

The loading of the ship must be done in accordance with（）.

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

The helm command PORT TWENTY means（）.

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

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

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

A tide is called diurnal when（）.