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: Calculations are described showing conversions between molar mass and density for gases. Question: Calculations are described showing conversions between molar mass and what for gases?
[A]: density


[Q]: Sentence: Cloud of these can make a shadow on the ground during the day. Question: Which of these can make a shadow on the ground during the day?
[A]: Cloud


[Q]: Sentence: Urea vertebrate animals metabolize ammonia what is the primary byproduct that is produced. Question: When vertebrate animals metabolize ammonia what is the primary byproduct that is produced?
[A]:
urea