You are given an elementary science question along with a few answer options. List all the words from the question that are essential and sufficient for choosing the correct answer option. Keep in mind that essential words are necessary to understand the meaning of the given question. However, non-essential words provide little information needed to select the correct answer. You can think about it like this: If the question was in another language, knowing the meaning of which words were necessary and enough for you to understand the question and answer it?. If your answer consists of multiple spans of words from the question, separate those using a comma (", "). Do not generate any word that is not present in the question. Make sure that your response is contained in the given question and the words are in the same order as the question.
 Grammatical correctness is not important.

Q: Question: What causes nighttime and daytime on Earth? (A) the Sun rotating on its axis (B) Earth rotating on its axis (C) Earth revolving around the Sun (D) the Moon revolving around Earth?

A: causes, nighttime, daytime, Earth?
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Q: Question: What should a student do when a glass beaker shatters during a laboratory experiment? (A) Notify the teacher. (B) Sweep the pieces into a pile. (C) Pick up the pieces and throw them away. (D) Leave it until the experiment is complete.?

A: student, glass, beaker, shatters, experiment?
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Q: Question: People can help keep a forest a good place for birds to live by (A) dumping garbage in a small part of the forest (B) building a road through the middle of the forest (C) burning dead trees to make smoke in the air (D) preventing too many trees from being cut down?

A:
keep, forest, good, birds
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