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'.
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Question: Question: *** *** *** *** *** ****** ****** ****** *** *** *** *** *** ***  (A) records from history. (B) natural motions of the sun. (C) natural motions of the Earth. (D) natural motion of the moon.

Answer: E.


Question: Question: Which *** help to destroy pathogens such as bacteria that enter the human body?  (A) red blood cells (B) liver cells (C) white blood cells (D) brain cell.

Answer: C.


Question: Question: A student notices that an *** *** *** *** when it is *** by a ***. Which best *** the *** of the *** as a *** of this ***?  (A) The mass of the balloon increases because the size of the balloon has increased. (B) The mass of the balloon increases because the temperature of the balloon has increased. (C) The mass of the balloon stays the same because the gas inside the balloon still has the same mass after it warms up. (D) The mass of the balloon stays the same because warming decreases the mass enough to cancel out the effect of increasing the size.

Answer:
E.