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

[Q]: The human eye detect can detect three colors of light.
[A]: How many colors of light can the human eye detect?


[Q]: Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only contract.
[A]: Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only do what?


[Q]: Right-end zeros do we call zeros that appear after nonzero digits.
[A]:
What do we call zeros that appear after nonzero digits?