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

[EX Q]: Solid is characterized by molecules with minimal movement and strong forces between them.
[EX A]: Which state of matter is characterized by molecules with minimal movement and strong forces between them?

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

[EX Q]: The electromagnetic spectrum represents the full range of frequency of electromagnetic waves.
[EX A]:
The electromagnetic spectrum represents the full range of frequency of what type of wave?