TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Poles parts of the planet does solar energy have difficulty reaching.

SOLUTION: What parts of the planet does solar energy have difficulty reaching?

PROBLEM: Filter feeders called rotifers collect digestive and excretory wastes in cloacal bladder primitive organ.

SOLUTION: Filter feeders called rotifers collect digestive and excretory wastes in what primitive organ?

PROBLEM: The creation of a voltage across a current-carrying conductor by a magnetic field is known as hall effect.

SOLUTION:
The creation of a voltage across a current-carrying conductor by a magnetic field is known as what?