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: Which animal is preparing for a *** *** in the environment?  (A) a bat flying at night (B) a deer drinking water (C) an owl eating a mouse (D) a squirrel storing nut.
[A]: D.


[Q]: Question: When an *** *** ***, it *** *** *** *** into the ***. The *** MOST *** *** the ***  (A) move quickly through the water. (B) breathe oxygen from the water. (C) hide from predators. (D) use food faster.
[A]: E.


[Q]: Question: Tobias rode his bike on a road for a 2 hr period. On average, he passed a *** *** marker every *** *** during this period. Which of the following was his *** speed for this 2 hr period?  (A) 10 km/hr (B) 15 km/hr (C) 20 km/hr (D) 25 km/h.
[A]:
E.