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

[Q]: Matter that mechanical wave energy can only travel through is medium.
[A]: What is the name of matter that mechanical wave energy can only travel through?


[Q]: Are humans a new or old species on the earth?
[A]: Are humans a new or old species on the earth?


[Q]: In science, motion is defined as a change in position.
[A]:
In science, what is defined as a change in position?