TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Light retains its original color under water because frequency remains the same when light is refracted.

SOLUTION: Light retains its original color under water because what remains the same when light is refracted?

PROBLEM: Glaciers deposit their sediment when they melt.

SOLUTION: When do glaciers deposit their sediment?

PROBLEM: We call the study of rock layers stratigraphy.

SOLUTION:
What do we call the study of rock layers?