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.
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Question: Sentence: Oxygen has increased in the atmosphere throughout the history of the earth. Question: What has increased in the atmosphere throughout the history of the earth?

Answer: oxygen


Question: Sentence: A sudden flow of mud is called a(n) mudflow. Question: What's it called when there's a sudden flow of mud?

Answer: mudflow


Question: Sentence: Precipitation and runoff in the water cycle are primarily responsible for the creation of a lake. Question: Which two processes in the water cycle are primarily responsible for the creation of a lake?

Answer:
precipitation and runoff