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

[Q]: Gardasil is the vaccine to prevent infection of hpv.
[A]: What is the vaccine to prevent infection of hpv?

[Q]: Renewable energy sources emit fewer or no greenhouse gases.
[A]: What type energy sources emit fewer or no greenhouse gases?

[Q]: Crystals is used by sensitive systems to detect even low levels of radiation.
[A]:
What is used by sensitive systems to detect even low levels of radiation?