单项选择题
A.shallow water B.deep water C.river D.tide
（）is not a type of tide.A.SEMIDIURNALB.DIURNALC.MIXEDD....
单项选择题（）is not a type of tide.
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
