單項選擇題The unit of duration of a dash in Morse Code is（）.

A.one and one-half times the length of a dot
B.twice the length of a dot
C.three times the length of a dot
D.four times the length of a dot


您可能感興趣的試卷

你可能感興趣的試題

1.單項選擇題The range of a SSB transmission is MOST affected by（）.

A.atmospheric noise and radiated power
B.the frequency band selected and time of day or night
C.interference and position of the moon
D.radiated power and nearness to shore

2.單項選擇題The light rhythm of Morse (A) is shown on（）.

A.preferred-channel buoys
B.starboard- or port-side buoys
C.special marks
D.safe water buoys

3.單項選擇題The following（）is a standard phrase.

A.You may enter fairway
B.You should enter fairway
C.ANSWER. It is permitted to enter fairway
D.You could enter fairway

4.單項選擇題The following（）is a standard phrase.

A.I may enter fairway
B.I might enter fairway
C.INTENTION. I will enter fairway
D.I will probably enter fairway

5.單項選擇題The Departure Report，required by vessels participating in AMVER，must be sent（）.

A.as soon as practicable on leaving port
B.prior to departure
C.within 24 hours of departure
D.within 12 hours of departure