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

Rod is the general shape of centrioles.
What is the general shape of centrioles?

Ionic compounds contain cations and anions rather than discrete neutral molecules.
Ionic compounds contain cations and anions rather than what?

The surface of the sun is much hotter than almost anything on earth.
How hot is it on the surface of the Sun?