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

[EX Q]: Neutrophils provide an early, rapid, and nonspecific defense against invading pathogens.
[EX A]: What provides an early, rapid, and nonspecific defense against invading pathogens?

[EX Q]: Pangaea began breaking apart 250 million years ago.
[EX A]: How many millions of years ago did pangaea begin breaking apart?

[EX Q]: Aluminosilicates are formed by replacing some of the si atoms in silicates by al atoms.
[EX A]:
Aluminosilicates are formed by replacing some of the si atoms in silicates by which atoms?