instruction:
Given a fact, create a question that can be answered using the fact. Construct the question such that it is unambiguous, has a unique answer and the answer can be given using the fact.
question:
Fact: as altitude increases , the temperature of the air will decrease
answer:
As altitude increases, the air temperature will do what?


question:
Fact: many vehicles emit pollution into the air
answer:
Pollution is?


question:
Fact: a tree can be replaced by planting a new tree
answer:

which of these would result in reversal of desertification?