单项选择题
A.high pressure system B.cold front C.warm front D.occluded front
Clouds that form as small white flakes or scaly globula...
单项选择题Clouds that form as small white flakes or scaly globular masses covering either small or large portions of the sky are（）.
A.cirrus B.cirrostratus C.altostratus D.cirrocumulus
Clouds are classified according to their（）.A.sizeB.mois...
单项选择题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，cirrost...
单项选择题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
