If a towing vessel and her tow are severely restricted in their ability to change course，they may show lights in addition to their towing identification lights. These additional lights may be shown if the tow is（）.

单项选择题How does the effect known as bank suction act on a single-screw vessel proceeding along a narrow channel?（）.

A.It pulls the bow toward the bank
B.It pushes the entire vessel away from the bank
C.It pulls the stern toward the bank
D.It heels the vessel toward the bank

单项选择题For the deepest water when rounding a bend in a river，you should navigate your vessel（）.

A.toward the inside of the bend
B.toward the outside of the bend
C.toward the center of the river just before the bend，then change course for the river's center after the bend
D.in the river's center

单项选择题Catenary as applied to tow lines denotes the（）.

A.dip of the line
B.stretch of the line
C.strain on the line
D.length of the line

单项选择题Besides saving distance along the track line，another advantage of the Scharnow Turn over the Williamson Turn in a man overboard situation because（）.

A.it is faster
B.it can be used in both the immediate action and the delayed action situations
C.in fog，if the turn is started as soon as the man goes over，the vessel will be at the point where he went over when the turn is completed
D.it returns the vessel to the original track line on a reciprocal course

单项选择题At night，a vessel shall indicate that she is restricted in her ability to maneuver by showing in a vertical line two（）.

A.red lights
B.red lights and two white lights
C.red lights with a white light in between
D.white lights with a red light in between