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

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

（）is halfway between the forward and after perpendiculars and is reference point for vessel construction.

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

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

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

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

（）is where the crew eat their meals.

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

Berthing means bringing a vessel to her berth until（）.