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

Example Input: Saturated hydrocarbons hydrocarbons contain only single bonds between carbon atoms.
Example Output: What hydrocarbons contain only single bonds between carbon atoms?

Example Input: Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only contract.
Example Output: Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only do what?

Example Input: The decayed remains of living organisms is called humus.
Example Output:
What is the decayed remains of living organisms called?