In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Q: Fact1: volcanic ash in the atmosphere decreases the temperature by blocking the sun, Fact2: Ash clouds are a particular problem for aircraft., Question: What are particular problems for aircraft in the atmosphere? (A) transportation (B) clog airways (C) extremely low humidity (D) volcanic clouds (E) feedback mechanisms (F) negative feedback (G) gas spreads in the air (H) very complex

A: D
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Q: Fact1: the Himalayas were formed by rock folding, Fact2: If the rocks are not as brittle, they will either tilt or fold., Question: What is the consistency of the Himalayan rocks? (A) crust (B) Loose (C) simple (D) cold (E) loose soil (F) Smooth (G) liquid (H) Brittle

A: H
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Q: Fact1: Cells cannot survive without oxygen., Fact2: Life is responsible for oxygen in the atmosphere., Question: What can't cells survive without? (A) money (B) atmosphere (C) vapor (D) friends (E) Energy. (F) Energy (G) Light (H) Chemical energy

A:
B
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