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

Q: Transpiration is when plant roots absorb liquid water and release water vapor into the atmosphere.

A: What is it called when plant roots absorb liquid water and release water vapor into the atmosphere?
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Q: The sum of the masses of the atoms in the formula is referred to as molecular mass.

A: The sum of the masses of the atoms in the formula is referred to as what?
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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?
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