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: Flagella help prokaryotes move., Fact2: Most prokaryotes are unicellular., Question: What helps unicellular organisms move? (A) evaporation (B) bacteria (C) heat energy (D) glucose (E) sweating (F) flagella (G) legs (H) blood

A: F
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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: Amphibians have a relatively complex circulatory system with a three-chambered heart., Fact2: All frogs are amphibians., Question: What has a relatively complex circulatory system with a three-chambered heart? (A) frogs (B) a fish (C) salmon (D) alpacas (E) Man (F) Birds (G) sharks (H) pan

A:
A
****