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

Diffusion process helps absorptive protists absorb food molecules across their cell membranes.
Which process helps absorptive protists absorb food molecules across their cell membranes?

Are humans a new or old species on the earth?
Are humans a new or old species on the earth?

Ice cubes are an example of the solid form of water.

Ice cubes are an example of which form of water?