Ques:You are presented with the question "What harms the respiratory and circulatory systems?" and the following answer choices: - oil - Cars - coal - water - air - sulfur - bees - dust Now knowing that air pollution harms the respiratory and circulatory systems and dust contributes to air pollution, choose the best answer.

Ans:dust
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Ques:You are presented with the question "What helps maintain body temperature?" and the following answer choices: - hats - Lift - the inside of a refrigerator - fur - skin - arctic winds - freezing water - hair Now knowing that an animal usually requires a warm body temperature for survival and mammals are also warm-blooded and are covered with hair or fur, choose the best answer.

Ans:fur
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Ques:You are presented with the question "What requires electrical energy to function?" and the following answer choices: - lemons - motors - LEDs - buses - rocks - hats - Cars - PDAs Now knowing that electric devices require electrical energy to function and examples of such devices are PDAs, phones, and pagers, choose the best answer.

Ans:PDAs
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Ques:You are presented with the question "What causes causes thermal expansion?" and the following answer choices: - molecules moving - kinetic energy - Electrical energy - Evaporation - molecules stopping - sunlight - molecules slowing down - molecules standing still Now knowing that increasing heat causes thermal expansion and heat is caused by molecules moving, choose the best answer.

Ans:
molecules moving
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