TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only contract.

SOLUTION: Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only do what?

PROBLEM: Darwin believed in gradualism.

SOLUTION: Did darwin believe in punctuated equilibrium or gradualism?

PROBLEM: Covalent solutes separate into individual molecules when dissolved.

SOLUTION:
Covalent solutes separate into what when dissolved?