How many hours of rest is the minimum required in a normal day?（）

单项选择题If the electronic chart is part of an ECDIS,it must display the minimum data required by IMO IHO,to include all of the following EXCEPT（）.

A.hydrography
B.aids to navigation
C.tidal currents
D.regulatory boundaries

单项选择题（）on still water indictes how loading weight distribution affects on longitudinal strength.

A.Bending moment
B.local strength
C.shear force
D.displacement

单项选择题ANCHOR HAS ITS OWN CABLE TWISTED AROUND IT defines（）.

A.foul of anchor
B.dropping anchor
C.weighing anchor
D.walking back anchor

单项选择题（）sends a radio signal from the bottom of the ship to the sea-bed,from which it is reflected.

A.The marine sextant
B.The chronometer
C.The echo sounder
D.The radar

单项选择题The ARPA may swap targets when automatically tracking if two targets（）

A.are tracked on reciprocal bearings
B.are tracked at the same range
C.are tracked on the same bearing
D.pass closely to each other