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

[Q]: The brain is the most complex organ in the human body.
[A]: What is the most complex organ in the human body?

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

[Q]: Objects on earth have two forces acting on them at all times.
[A]:
How many forces do objects on earth have acting on them at all times?