You are given a question, its answer, and a sentence that supports the question, i.e., the answer to the question is inferable from the sentence. In this task, you need to paraphrase the given sentence so that the paraphrased sentence still supports the question i.e. you can still infer the answer to the question from the paraphrased sentence. Do not write a paraphrase with a minor change in the given sentence e.g. replacing the word "one" with "a". Instead, try to write a paraphrase that contains new words, i.e. the words that are not present in the input sentence.

Q: Question: What process is most responsible for the extinction of most species of plants and animals that have lived on Earth? 
Answer: environmental changes. 
Sentence: Environmental changes is most responsible for the extinction of most species of plants and animals that have lived on earth.

A: Environmental changes are the main reason why plants and animals, that have lived on the earth, have gone extinct.
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Q: Question: What occurs when excess carbon dioxide in the atmosphere causes the oceans to become acidic? 
Answer: ocean acidification. 
Sentence: Ocean acidification occurs when excess carbon dioxide in the atmosphere causes the oceans to become acidic.

A: A more acidic ocean as a result of excess carbon dioxide in the atmosphere is known as ocean acidification.
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Q: Question: Moss is best classified as —? 
Answer: a nonvascular plant. 
Sentence: Moss is best classified as a nonvascular plant.

A:
A nonvascular plant is called a moss.
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