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: What occurs when a substance reacts quickly with oxygen? Answer: combustion reaction
[A]: Combustion reaction occurs when a substance reacts quickly with oxygen.


[Q]: Question: Electrophiles have a strong tendency to react with what? Answer: nucleophiles
[A]: Electrophiles have a strong tendency to react with nucleophiles.


[Q]: Question: What astronomical phenomenon is often comprised of remnants of the earliest material that formed in the solar system? Answer: meteorites
[A]:
Meteorites are often comprised of remnants of the earliest material that formed in the solar system.