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: An *** that can *** the *** of an ***, such as its speed or direction, is called ___.  (A) solubility (B) buoyancy (C) force (D) potential energ.

A: D.
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Q: Question: *** *** *** following activities *** harmful *** *** environment?  (A) recycling waste (B) conserving water (C) producing waste (D) reducing pollutio.

A: C.
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Q: Question: Which *** below would be the best *** to *** if an ***, *** ***, a *** of ***, or a *** would *** on water?  (A) observing each object in water (B) measuring the size of each object (C) calculating the weight of the objects (D) comparing the shapes of the object.

A:
E.
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