单项选择题
A.cold front B.warm front C.tropical front D.occluded front
Brief，violent showers frequently accompanied by thunder...
单项选择题Brief，violent showers frequently accompanied by thunder and lightning are usually associated with（）.
A.passage of a warm front B.passage of a cold front C.winds shifting counterclockwise in the Northern Hemisphere D.stationary high pressure systems
As a cold front passes an observer，pressure（）.A.drops a...
单项选择题As a cold front passes an observer，pressure（）.
A.drops and winds become variable B.rises and winds become gusty C.drops and winds become gusty D.rises and winds become variable
An occluded front is usually caused by a（）.A.cold front...
单项选择题An occluded front is usually caused by a（）.
A.cold front becoming stationary B.warm front becoming stationary C.cold front overtaking a warm front D.warm front dissipating
