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clouds 
Fine droplets of water or ice crystal suspended in the atmosphere; the World Meteorological Organization classifies them according to 10 types.
clouds of vertical development
Clouds whose base is at low altitude but extend very high; the two types are cumulus and cumulonimbus.
cumulonimbus
Very imposing cloud that can reach a thickness of 10 km and whose base is very dark; it can trigger violent precipitation.
cumulus
Fair-weather cloud with very clear contours; it has a gray, flat base and a white top with rounded protuberances.
