In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Q: Question: Which of these is the BEST sign that the fall season has begun? Answer: Leaves changing color on trees

A: Leaves changing color on trees of these is the best sign that the fall season has begun.
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Q: Question: What forms when nitrogen and oxygen combine at high temperatures? Answer: nitrogen oxide

A: Nitrogen oxide form(s) when nitrogen and oxygen combine at high temperatures.
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Q: Question: What is it called when you touch a charged object to the earth? Answer: grounding

A:
Grounding is when you touch a charged object to the earth.
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