Cyclones tend to move（）.

A. perpendicular to the isobars in their warm sectors
B. parallel to the isobars in their warm sectors
C. parallel to the line of the cold front
D. perpendicular to the line of the cold front

Clouds are classified according to their（）.

A. size
B. moisture content
C. altitude and how they were formed
D. location in a front

Clouds appearing in the following order: cirrus，cirrostratus，altostratus，stratus，and nimbostratus usually indicate the approach of a(n)（）.

A. warm front
B. occluded front
C. medium front
D. cold front

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 system

An occluded front is caused by a(n)（）.

A. low pressure area
B. high pressure area
C. area of calm air
D. cold front overtaking a warm front

An atoll cloud forming over an island due to heating of the land during the daytime would be which type? （）

A. Cirrus
B. Cumulus
C. Stratus
D. Nimbu

A sea breeze is a wind（）.

A. that blows towards the sea at night
B. that blows towards an island during the day
C. caused by cold air descending a coastal incline
D. caused by the distant approach of a hurricane

A boundary between two air masses is a(n)（）.

A. lapse rate
B. isobar
C. front
D. continent

进行系统配置时有那些方法？具体含义是什么？

Cirrus clouds followed by cirrostratus then altostratus，stratus，and occasionally nimbostratus indicate the approach of a(n)（）.

A. cold front
B. warm front
C. tropical front
D. occluded front