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

Example Input: Oxygen gas is given off by plants.
Example Output: Which gas is given off by plants?

Example Input: One of the properties of an air mass is that an air mass has similar temperature and moisture properties throughout it.
Example Output: Which of the following is true regarding the properties of an air mass?

Example Input: The quantum model atomic model shows that the distances of electrons from the nucleus is not a fixed value.
Example Output:
Which atomic model shows that the distances of electrons from the nucleus is not a fixed value?