What is an element? carbon dioxide, hurdrogen, water, or air

In russia which of these challenges affects the transportation of both petroleum products and other goods?

Which component of a milankovitch cycle is related to periodic ice ages throughout earth’s history?

Altocumulus, altostratus, cirrocumuls, cirrostratus, cirrus, cumulonimbus, cumulus, nimbostratus, stratocumulus, stratus 8.) clouds with tallest vertical development 9.) low altitude clouds in solid layers that produce rain 10.) high altitude thin flat layers of clouds 11.) rain clouds that form under stable atmospheric conditions 12.) middle altitude clouds with globular appearance