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

What is it called when it is possible to ignite the vapour above the oil?（）

（）is on the panel of radar.

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

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

ECDIS must be able to perform all of the following EXCEPT（）.

In the Northern hemisphere northerly winds may cause temperature（）.

（）is the act of allocating space to containers on board of a container ship in the order of the discharge ports.

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

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