In this task, you need to answer basic science questions. For each question, several terms are intentionally masked with ***. This masking can cover very few or many of the question words. Clearly, if masked terms are important, the modified question will be impossible to answer. Please indicate the correct answer with one of the following responses: "A", "B", "C", "D" or "E". While "A"-"D" correspond to the answer options provided in the input, "E" represents "I don't know" for questions that do not provide enough information. Respond via "E" if the question is not answerable. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'.

Q: Question: Diatoms are microorganisms that produce *** through the process of ***. *** are an example of a *** that is __________.  (A) visible to the naked eye (B) disease-causing in humans (C) a primary producer (D) responsible for decompositio.

A: E.
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Q: Question: A student perfoms an *** by *** *** *** different amounts of *** for a ***. At the *** of the ***, she *** the *** mice. *** the *** is an *** of  (A) a measurement (B) a hypothesis (C) an explanation (D) background researc.

A: E.
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Q: Question: What precaution must be taken by students when making observations of the Sun?  (A) Use only new equipment. (B) Use a very strong telescope. (C) Project image onto a piece of cardboard. (D) Look at the Sun only in the morning.

A:
C.
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