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

[Q]: Seismologists originally measured the intensity of an earthquake with the mercalli scale.
[A]: How did seismologists originally measure the intensity of an earthquake?


[Q]: The behavior of ideal gases is explained by kinetic molecular theory.
[A]: The behavior of ideal gases is explained by what theory of gases?


[Q]: Nonvascular plants reproduce with spores.
[A]:
What do nonvascular plants reproduce with?