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

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（）.

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

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

Which wind results from a land mass cooling more quickly at night than an adjacent water area?（）

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

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

（）is on the panel of radar.

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