instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Cancer occurs most often in adults over fifty age.
answer:
Cancer occurs most often in adults over what age?


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


question:
The photic zone extends 200 meters deep.
answer:
How many meters deep does the photic zone extend?