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

[EX Q]: Terrestrial biomes are associated with land, while aquatic ones are associated with water.
[EX A]: Terrestrial biomes are associated with land, while aquatic ones are associated with what?

[EX Q]: Chordates include vertebrates and invertebrates that have a notochord.
[EX A]: Chordates include vertebrates and invertebrates that have what?

[EX Q]: Because the current is alternating, the magnetic field of the iron core keeps doing reversing.
[EX A]:
Because the current is alternating, the magnetic field of the iron core keeps doing what?