Answer:
Hot, humid air rises over the equator. As it rises to high altitude it expands because the air pressure decreases (there is less mass of air above it). As air expands due to this decreasing pressure, it also cools. Since cool air is able to hold less water vapor than warm air, condensation occurs.
Answer:
d. the accumulation of greenhouse gases in the earth's atmosphere.
Explanation:
They give us more information about what they learned.