During daylight hours, birds______.A．wheel back and forth for nothingB．do not fly long dis

A vessel not under command shall display ______.

A.two red lights at night and two black balls during daylight

B.two red lights at night and three black balls during daylight

C.three red lights at night and two black balls during daylight

D.three red lights at night and three black balls during daylight

During daylight hours, birds __________

A. fly aimlessly

B. rely on landmarks

C. rely on the sun for guidance

D. are more likely to get lost

______.

A.west in west longitude and east in east longitude

B.east in west longitude and west in east longitude

C.west

D.east

s can be made to last longer by ______.

A.unscrewing the bulb during the daylight

B.switching the light on only when necessary

C.taking no action as there is no way on saving power

D.taking no action as they shut off automatically in daylight

In using Loran-C，skywave reception gives greater range but is ______．

A.only accurate during daylight hours

B.much less accurate

C.only accurate at twilight

D.more accurate than using ground waves

vessel being hand-steered during daylight hours in good visibility and clear of any navigational hazards，the lookout may be ______.

A.the helmsman

B.the mate on watch

C.Either A or B

D.Neither A nor B

ot cargo vessel with an unobstructed view astern from the steering position. The vessel is being hand-steered during daylight hours in good visibility and clear of any navigational hazards. The lookout may be ______.

A.the helmsman

B.the officer on watch

C.either A or B

D.neither A nor B

A passenger vessel is underway. When may passengers visit the pilothouse？

A.Passengers are excluded from the pilothouse while underway

B.Passengers are permitted in the pilothouse during daylight hours only

C.Passengers are permitted to visit the pilothouse when authorized by the Master and officer of the watch

D.Passengers are permitted in the pilothouse when they are escorted by a ship's officer

A.when

B.that

C.before

D.while