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

Ex Input:
A decline in blood flow to kidneys organs stimulates release of the enzyme renin, in turn stimulating the reabsorption of sodium and water.

Ex Output:
A decline in blood flow to what organs stimulates release of the enzyme renin, in turn stimulating the reabsorption of sodium and water?


Ex Input:
Chemical digestion mainly occurs in the small intestine.

Ex Output:
Where does chemical digestion mainly occur?


Ex Input:
Calcium nitrate is composed of a calcium cation and a nitrate anion.

Ex Output:
What is composed of a calcium cation and a nitrate anion?