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

Ex Input:
Macroevolution happens when forces of evolution work over a long period of time.

Ex Output:
What happens when forces of evolution work over a long period of time?


Ex Input:
Muscle groups are controlled by the motor cortex .

Ex Output:
Muscle groups are controlled by what mechanism?


Ex Input:
When a fluorine atom gains an electron, it becomes a negative fluoride ion.

Ex Output:

When a fluorine atom gains an electron, it becomes a negative what?