航海英语潮汐与涌浪单项选择题每日一练(2018.11.15)

单项选择题
Priming of the tides occurs（）.
A.at times of new and full Moon
B.when the Earth，Moon，and Sun are lying approximately on the same line
C.when the Moon is between first quarter and full and between third quarter and new
D.when the Moon is between new and first quarter and between full and third quarter
单项选择题
Current refers to the（）.
A.vertical movement of the water
B.horizontal movement of the water
C.density changes in the water
D.None of the above
单项选择题
The velocity of a rotary tidal current will be decreased when the Moon is（）.
A.at apogee
B.new
C.full
D.All of the above
单项选择题
Currents are（）in rate and direction.
A.vary
B.variable
C.variably
D.variability
单项选择题
Stand of the tide is that time when（）.
A.the vertical rise or fall of the tide has stopped
B.slack water occurs
C.tidal current is at a maximum
D.the actual depth of the water equals the charted depth