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

Changing the shape of an elastic material gives it potential energy.
Changing the shape of an elastic material gives it what type of energy?

Water leaves ponds and lakes through evaporation and also as outflow.
Water leaves ponds and lakes through evaporation and also as what?

The photic zone extends 200 meters deep.
How many meters deep does the photic zone extend?