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'.

Question: Clouds bring rain and snow to Earth's surface. How do rain and snow most support *** on Earth?  (A) They cool the land surface. (B) They carry acids into the soil. (C) They bring freshwater to land organisms. (D) They build up mountains.
C.

Question: In humans, the digestion process begins in  (A) the intestine, with squeezing. (B) the mouth, with chewing and saliva. (C) the stomach, with churning and acid. (D) the esophagus, with pushing towards the stomach.
B.

Question: The systems of the human body work together. Which *** works with the *** *** by pulling on the *** to create ***?  (A) digestive (B) circulatory (C) muscular (D) nervou.

E.

