单项选择题
A.SEMIDIURNAL B.DIURNAL C.MIXED D.OSCILLATING
Water may boil up around the stern of a vessel in a cha...
单项选择题Water may boil up around the stern of a vessel in a channel due to（）.
A.slack water when upbound B.shallow water C.a cross current D.a head current
Tropic tides are caused by the（）.A.Moon being at its ma...
单项选择题Tropic tides are caused by the（）.
A.Moon being at its maximum declination B.Moon crossing the equator C.Sun and Moon both being near 0°declination D.Moon being at perigee
To make sure of getting the full advantage of a favorab...
单项选择题To make sure of getting the full advantage of a favorable current，you should reach an entrance or strait at what time in relation to the predicted time of the favorable current?（）
A.One hour after the predicted time B.At the predicted time C.30 minutes before flood，one hour after an ebb D.30 minutes before the predicted time
