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

[EX Q]: On a global scale, plants and other photosynthetic organisms have generated all of the oxygen in the air.
[EX A]: On a global scale, plants and other photosynthetic organisms have generated all of what element in the air?

[EX Q]: A decline in blood flow to kidneys organs stimulates release of the enzyme renin, in turn stimulating the reabsorption of sodium and water.
[EX A]: A decline in blood flow to what organs stimulates release of the enzyme renin, in turn stimulating the reabsorption of sodium and water?

[EX Q]: A heterogeneous mixture of particles of one substance distributed throughout a second substance in a different phase is known as suspension.
[EX A]:
A heterogeneous mixture of particles of one substance distributed throughout a second substance in a different phase is known as what?