Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[EX Q]: In the tropics tradewinds are the prevailing winds called.
[EX A]: In the tropics what are the prevailing winds called?

[EX Q]: Oil is the most commonly used source of energy in the world.
[EX A]: What is the most commonly used source of energy in the world?

[EX Q]: Temperature is too cold is there very little evaporation in the boreal forests.
[EX A]:
Why is there very little evaporation in the boreal forests?