Q: Fact 1: Temperature falls from the equator to the poles. Fact 2: All temperatures are measures of heat energy. Given the two facts above, what falls from the equator to the poles?

Choose your answer from:
+ precipitation.
+ heat energy.
+ Greenhouse gases.
+ sunlight.
+ carbon dioxide.
+ water vapor.
+ sun's heat.
+ energy.
The answer is:
heat energy