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

Input: Consider Input: Single-celled organisms and multicellular organisms have this in common: both have a way to get rid of waste materials.

Output: Which characteristic do single-celled organisms and multicellular organisms have in common?


Input: Consider Input: Cranium (skull) is the term for the skeletal structure of the head that supports the face and protects the brain.

Output: What is the term for the skeletal structure of the head that supports the face and protects the brain?


Input: Consider Input: The values of independent variables are controlled by the experimenter over the course of an experiment.
Output: The values of which factors are controlled by the experimenter over the course of an experiment?