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.

Question: John was using his mp3 player when it suddenly stopped working. What is the first thing John should do to try correcting the problem? (A) recharge the battery (B) take the player apart (C) replace the player with a new one (D) change to a different song?
mp3, player, stopped, working., first, correcting, problem?

Question: Which best describes a characteristic of the jet stream? (A) It forms a boundary between a cold air mass and a warm air mass. (B) It creates the high winds around the eye of a hurricane. (C) It forces the hot air along the equator to rise to areas in North America. (D) It causes high pressure air masses to rotate clockwise.?
characteristic, jet, stream?

Question: The prairie grass ecosystem once had a deep layer of topsoil which was protected by the grasses that covered it. Removal of these grasses for farmland is causing the soil to be eroded mainly by (A) wind and rain. (B) animal movement. (C) crops grown in the soil. (D) increased temperatures.?

ecosystem, grasses, Removal, grasses, farmland, soil, eroded