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(单选题)What do you think the old man was? (单选题)What is the possible reason why the sparrow did not follow t (单选题)From the text we can learn the following ______. (单选题)Why did Time Magazine name Albert Einstein “person of the ce (单选题)Of the five smartest people, who put forward theories relate (单选题)What is the author’s attitude towards the development of the (单选题)What is the fourth paragraph mainly about? (单选题)What can the paper-based batteries do? (单选题)What makes the paper-based batteries different from other ba (单选题)What is the main idea of the passage?