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 gas is given off by plants? Answer: Oxygen

A: Oxygen gas is given off by plants.
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Q: Question: What type of device uses electromagnetic induction to change the voltage of electric current? Answer: electronic transformer

A: A electronic transformer uses electromagnetic induction to change the voltage of electric current.
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Q: Question: How many valence electrons can be found in a carbon atom? Answer: four

A:
Four valence electrons can be found in a carbon atom.
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