A.Carbon dioxideB.Dry chemicalC.FoamD.All of the aboveA……

单项选择题An azimuth angle for a body is measured from the（）.

A.observer's meridian
B.Greenwich meridian
C.body's meridian
D.zenith distance

单项选择题An authorized light to assist in the identification of submarines operating on the surface is a(n)（）.

A.blue rotating light
B.intermittent flashing amber/yellow light
C.flashing white light
D.flashing sidelight

单项选择题An aneroid barometer on a boat should always be（）.

A.located in an air-conditioned area
B.mounted in the passenger compartment
C.protected by a collision bulkhead
D.permanently mounted

单项选择题An anchored vessel is servicing an aid to navigation and is restricted in her ability to maneuver. Which lights will she show? （）

A.Three lights in a vertical line，the highest and lowest red and the middle white，and anchor lights
B.Three lights in a vertical line，the highest and lowest red and the middle white，ONLY
C.Anchor lights ONLY
D.Anchor lights and sidelights ONLY

单项选择题An all-round flashing yellow light may be exhibited by a(n)（）.

A.vessel laying cable
B.vessel towing a submerged object
C.vessel not under command
D.air cushion vessel