The force resulting from the earth’s rotation that causes winds to deflect to the right in the Northern Hemisphere and to the left in the Southern Hemisphere is called（）.

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

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

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

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

The helm command PORT TWENTY means（）.

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

A tide is called diurnal when（）.

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

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