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

The pupil is the name of the black opening in the eye that lets light enter.
What is the name of the black opening in the eye that lets light enter?

You call the separation of ions that occurs when a solid ionic compound dissolves dissociation.
What do you call the separation of ions that occurs when a solid ionic compound dissolves?

Human actions is responsible for the extinction of hundreds of species of birds.

Which single most factor is responsible for the extinction of hundreds of species of birds?