instruction:
In this task, you are given a question and a corresponding answer. Your task is to generate a fact statement that is useful in answering the given question.
question:
Question: What is a source of oxygen through photosynthesis? Answer: sunflowers.
answer:
plants are a source of oxygen through photosynthesis


question:
Question: Which likely increased atmospheric CO2 recently? Answer: motorcycles.
answer:
carbon dioxide concentrations in the air have increased over the last decade dramatically


question:
Question: Electricity causes less pollution than what? Answer: car propellant.
answer:

electricity causes less pollution than gasoline