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

[EX Q]: Water seeping into the ground is known as infiltration.
[EX A]: Water seeping into the ground is known as?

[EX Q]: A diploid cell is a cell with two chromosomes.
[EX A]: What kind of cell is a cell with two chromosomes?

[EX Q]: Mass matter reacts, there can be what that comes from nowhere and is unaccounted for.
[EX A]:
When matter reacts, there can be what that comes from nowhere and is unaccounted for?