In this task, you are given a sentence and a question, you would be asked to create the answer which is contained in the sentence provided.

[Q]: Sentence: Proteins are long chains of amino acids. Question: What are long chains of amino acids?
[A]: proteins


[Q]: Sentence: Weight is the force of gravity. Question: What is the force of gravity called?
[A]: weight


[Q]: Sentence: Very low density is the concentration of gas molecules in the mesosphere. Question: What is the concentration of gas molecules in the mesosphere?
[A]:
very low density