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

[Q]: Pyramid ecosystem is used to show energy flow through the trophic levels.
[A]: What is used to show energy flow through the trophic levels?


[Q]: Solids are categorized by the forces holding the individual atoms, ions, or molecules together.
[A]: What is categorized by the forces holding the individual atoms, ions, or molecules together?


[Q]: Solution is the term for a homogeneous mixture of two or more substances.
[A]:
What is the term for a homogeneous mixture of two or more substances?