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（）.

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

单项选择题Vapor given off by a flammable liquid will burn when ignited provided（）

A.the vapor and air mixture is too rich
B.it is mixed with certain proportions of air
C.the vapor is too little compared to the air
D.it is of heavy toxicity