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: The structure of mitochondrion plays an important role in what? Answer: aerobic respiration
[A]: The structure of mitochondrion plays an important role in aerobic respiration.


[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.


[Q]: Question: When matter reacts, there can be what that comes from nowhere and is unaccounted for? Answer: mass
[A]:
Mass matter reacts, there can be what that comes from nowhere and is unaccounted for.