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

[Q]: A concave lens is thicker at the edges than it is in the middle.
[A]: What type of lens is thicker at the edges than it is in the middle?


[Q]: Injuries can be prevented by getting proper rest and recovery.
[A]: Injuries can be prevented by getting proper what?


[Q]: Precipitation and runoff in the water cycle are primarily responsible for the creation of a lake.
[A]:
Which two processes in the water cycle are primarily responsible for the creation of a lake?