单选题
The four families of clouds are ( ) .
A
stratus, cumulus, nimbus, and cirrus
B
clouds formed by updrafts, fronts, cooling layers of air, and precipitation into warm air
C
high, middle, low, and those with extensive vertical development
D
altocumulus, nimbostratus, cirrus, and towering cumulus
答案解析
正确答案:C
