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 can be used to determine the mass of a quantity of material? Answer: molar masses
[A]: Molar masses can be used to determine the mass of a quantity of material.

[Q]: Question: What structures are located on roof of the nasopharynx and on each side of the pharynx? Answer: tonsils
[A]: Tonsils structures are located on roof of the nasopharynx and on each side of the pharynx.

[Q]: Question: What is the amount of energy required to begin a chemical reaction known as? Answer: activation energy
[A]:
The amount of energy required to begin a chemical reaction is known as the activation energy.