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.


[Q]: Question: How many protons and electrons each do carbon atoms have? Answer: six
[A]: Carbon atoms have six protons and electrons each.


[Q]: Question: What is formed when a subducting plate flows under another tectonic plate? Answer: volcanic arc
[A]:
A volcanic arc is formed when a subducting plate flows under another tectonic plate.