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

Q: Interstitial fluid are all hormones secreted into before entering the circulatory system.

A: Where are all hormones secreted into before entering the circulatory system?
****
Q: When the phosphorus element - whose name means "light bringing" - was first isolated, scientists noted that it glowed in the dark and burned when exposed to air

A: When what element - whose name means "light bringing" - was first isolated, scientists noted that it glowed in the dark and burned when exposed to air?
****
Q: Gas phase is pure chlorine present as.

A:
What phase is pure chlorine present as?
****