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

Example Input: Multiple genes mutations is usually necessary to develop cancer.
Example Output: What is usually necessary to develop cancer?

Example Input: Constructive forces type of forces are involved when deposited rock forms deltas or barrier islands.
Example Output: What type of forces are involved when deposited rock forms deltas or barrier islands?

Example Input: Are cats more active at night than during the day? of the following questions is testable in a scientific investigation.
Example Output:
Which of the following questions is testable in a scientific investigation?