The mean draft of a ship is the draft（）.

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

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

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

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

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

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

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

According to the relevant regulation, lifeboat should be powered by（）.

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