instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
The frequency of a wave is the reciprocal of the period of the wave.
answer:
The frequency of a wave is the reciprocal of what other attribute of the wave?


question:
Plasma membranes encloses and defines the borders of cells.
answer:
What encloses and defines the borders of cells?


question:
Biomass can also be processed to make biofuel.
answer:

Biomass can also be processed to make what kind of fuel?