单项选择题
A.notify the competent authorities B.sound the alarm C.have passengers put on life preservers D.cut off air supply to the fire
If two sailing vessels are running free with the wind o...
单项选择题If two sailing vessels are running free with the wind on the same side, which one must keep clear of the other?（）.
A.The one with the wind closest abeam B.The one to windward C.The one to leeward D.The one that sounds the first whistle signal
If your weather bulletin shows the center of a low pres...
单项选择题If your weather bulletin shows the center of a low pressure area to be 100 miles due east of your position, what winds can you expect in the northern hemisphere?（）.
A.East to northeast B.East to southeast C.North to northwest D.South to southeast
In 1979 an extensive（）program was in progress throughou...
单项选择题In 1979 an extensive（）program was in progress throughout Suez Canal.
A.a dredge and widen B.dredged and widened C.dredging and widening D.being dredging and widening
