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 makes nobel gases unreactive? Answer: its electon configuration
[A]: Its electon configuration makes nobel gases unreactive.


[Q]: Question: What play an important role in the modulation of the nuclear chain reaction? Answer: control rods
[A]: Control rods play an important role in the modulation of the nuclear chain reaction.


[Q]: Question: What do we call the study of rock layers? Answer: stratigraphy
[A]:
We call the study of rock layers stratigraphy.