Given a statement, generate a question such that the answer is contained in that statement.

[Q]: Stomata shutting reduces transpiration.
[A]: What shutting reduces transpiration?


[Q]: cloth-edged screens are used for separating compilations
[A]: What type of screens are used for separating compilations?


[Q]: Condoms make copulation safe if they're not used incorrectly.
[A]:
What makes copulation safe if they're not used incorrectly?