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: *** material *** *** *** natural resource *** use *** making water-resistant shoes?  (A) cotton (B) leather (C) plastic (D) woo.

A: B.
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Q: Question: A student plans to design a new toothpaste tube that will give the same amount of toothpaste every time it is squeezed. Which should the student do first when designing the new tube?  (A) make a data table of amounts of toothpaste (B) gather building materials (C) create models of old toothpaste tubes (D) draw a few possible solution.

A: D.
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Q: Question: *** conserve *** supply *** nonrenewable resources*** *** *** *** *** recycle  (A) newspapers. (B) phonebooks. (C) paper towels. (D) soda cans.

A:
E.
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