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

[Q]: A skeleton that consists of hard, mineralized structures located within the soft tissue of organisms is called endoskeleton.
[A]: A skeleton that consists of hard, mineralized structures located within the soft tissue of organisms is called what?


[Q]: The sun is considered the center of the solar system.
[A]: What is considered the center of the solar system?


[Q]: Condensation must occur for clouds to form.
[A]:
Which process must occur for clouds to form?