Five or more short blasts on a vessel’s whistle indicates that she is（）.

单项选择题Every vessel which is directed by these Rules to keep out of the way of another vessel shall，if the circumstances of the case admit，avoid（）.

A.Crossing ahead of the other
B.Crossing astern of the other
C.Passing port to port
D.Passing starboard to starboard

单项选择题Every vessel which is（）to keep out of the way of another vessel shall，so far as possible，take early and substantial action to keep well clear.

A.detected
B.decided
C.directed
D.deceased

单项选择题Every vessel shall（）maintain a proper look-out by sight and hearing as well as by all available means appropriate in prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.

A.in fog
B.at night
C.in narrow fairway
D.at all times

单项选择题During the day，a vessel picking up a submarine cable shall carry（）.

A.Three shapes，the highest and lowest shall be red balls，and the middle shall be a white diamond
B.Two black balls
C.Three shapes；the highest and lowest shall be black balls，and the middle shall be a red diamond
D.Three shapes；the highest and lowest shall be black balls and the middle shall be a black diamond

单项选择题Dring a period of “whiteout”，you should expect which of the following（）.

A.Snowfall or blowing snow
B.Lack of ability to estimate distance
C.Harsh contrast between sun-illuminated snow cover and the background
D.Hazy horizons with extensive mirage effects