Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Most protein antigens require signals from helper t cells (th2) to proceed to make antibody.

Answer: Most protein antigens require signals from helper t cells (th2) to proceed to make what?


Question: Pheromones enable communication, which is vital for organisms like ants that live in a large community.

Answer: Pheromones enable what, which is vital for organisms like ants that live in a large community?


Question: When explosion of gases creates pressure resulting in motion of a rocket, the force pushing the rocket is called thrust.

Answer:
When explosion of gases creates pressure resulting in motion of a rocket, the force pushing the rocket is called what?