Write an incorrect answer to the given question based on the associated fact. You are also provided with the correct answer to the given question. Make sure that your incorrect answer is relevant and similar to the associated fact. Also, try to make the incorrect answer similar to the correct answer so that distinguishing the correct answer from the incorrect answer is not very easy. Make sure you don't accidentally provide another correct answer! Also, make sure they sound reasonable (e.g., might be on a school pop quiz). A good incorrect answer can be constructed using words associated with the question, but not the correct answer. For example, for the question "What helps plants survive?", using words like "weeds", "vase", "bee" (associated with "plant"), or "first aid", "parachute", "accident" (associated with "survive") etc. Your incorrect answers make the question hard, so these results in good incorrect answers.

Q: Fact: Gases from burning coal and oil dissolving in water in the atmosphere causes polluted rain. 
Question: Gases from burning coal and and oil dissolving in the atmosphere can cause what? 
Correct Answer: polluted rain.

A: humidity.
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Q: Fact: Napa and Sonoma were formed by a river flowing. 
Question: what were formed by a river flowing? 
Correct Answer: Napa and Sonoma.

A: Rockies.
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Q: Fact: if an object can be focussed on the retina, it can be seen. 
Question: what does it mean if an object can be focussed on the retina? 
Correct Answer: it can be seen.

A:
it has density.
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