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.
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Question: Question: Michael Faraday showed how electric current in a wire produces (A) molecules (B) chemicals (C) a vibration (D) a magnetic field?

Answer: electric, current, wire, produces


Question: Question: In the human body, the breaking down of food into simple substances occurs in the (A) digestive system. (B) excretory system. (C) circulatory system. (D) respiratory system.?

Answer: breaking, food, substances, occurs


Question: Question: Archaeologists use observation and inference to study the past. When archaeologists find objects, they __________. (A) usually infer that the people who used the objects were farmers (B) can make inferences about those who used the objects (C) make inferences about the size, color and shape of the objects (D) observe the behavior of the people as they use the objects.?

Answer:
Archaeologists, observation, inference, study, past., find