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

[EX Q]: A change of season and less food usually cause certain animals to migrate.
[EX A]: Which two environmental changes usually cause certain animals to migrate?

[EX Q]: Resonance is the term for the use of two or more lewis structures to represent the covalent bonding in a molecule.
[EX A]: What is the term for the use of two or more lewis structures to represent the covalent bonding in a molecule?

[EX Q]: Ecological pyramids can demonstrate the decrease in energy, biomass or numbers within an ecosystem.
[EX A]:
What can demonstrate the decrease in energy, biomass or numbers within an ecosystem?