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

[Q]: Most protein antigens require signals from helper t cells (th2) to proceed to make antibody.
[A]: Most protein antigens require signals from helper t cells (th2) to proceed to make what?


[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]: Newton’s second law of motion is more than a definition; it is a relationship among acceleration, force, and mass.
[A]:
Newton’s second law of what is more than a definition; it is a relationship among acceleration, force, and mass?