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

[Q]: Certain air pollutants form acid liquid when dissolved in water droplets in the air.
[A]: Certain air pollutants form which liquid when dissolved in water droplets in the air?

[Q]: Saturated hydrocarbons hydrocarbons contain only single bonds between carbon atoms.
[A]: What hydrocarbons contain only single bonds between carbon atoms?

[Q]: Black light color light is actually the absence of electromagnetic waves in the visible spectrum, for humans.
[A]:
What color light is actually the absence of electromagnetic waves in the visible spectrum, for humans?