航海英语海上天气现象单项选择题每日一练(2018.11.09)

单项选择题
Cumulus clouds that have undergone vertical development and have become cumulonimbus in form，indicate（）.
A.clearing weather
B.that a warm front has passed
C.probable thunderstorm activity
D.an approaching hurricane or typhoon
单项选择题
（）forms over land，most frequently during autumn and winter over low-lying land，especially if it is damp and marshy and in valleys on quiet nights with clear skies.
A.FRONTAL FOG
B.MIXING FOG
C.ADVECTION FOG
D.RADIATION FOG
单项选择题
A（）is created by a pressure gradient or slope in the water level.
A.gradient current
B.density current
C.swift current
D.torrent current
单项选择题
In the relatively calm area near the hurricane center，the seas are（）.
A.moderate but easily navigated
B.calm
C.mountainous and confused
D.mountainous but fairly regular as far as direction is concerned
单项选择题
Which type of precipitation is a product of the violent convection found in thunderstorms（）.
A.Snow
B.Freezing Rain
C.Hail
D.Sleet