TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: A bow wake is created when the wave source moves faster than the wave propagation speed.

SOLUTION: What is created when the wave source moves faster than the wave propagation speed?

PROBLEM: Population is an important level of organization in ecology and the unit of microevolution.

SOLUTION: What is an important level of organization in ecology and the unit of microevolution?

PROBLEM: Evenly spaced lines kind of lines does a diffraction grating produce.

SOLUTION:
What kind of lines does a diffraction grating produce?