Given a scientific question, generate a correct answer to it.

[EX Q]: During glycolysis, each glucose molecule is broken down into two molecules of what compound?
[EX A]: pyruvate

[EX Q]: What is a sac-like organ that stores urine?
[EX A]: the urinary bladder

[EX Q]: What is the process by which a liquid changes to a solid?
[EX A]:
freezing