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

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

Transpiration is when plant roots absorb liquid water and release water vapor into the atmosphere.
What is it called when plant roots absorb liquid water and release water vapor into the atmosphere?

The equator on earth receives the most direct sunlight.

Which location on Earth receives the most direct sunlight?