第18题: [单项选择]A comet is distinguished from other bodies in the solar system ______. A. into its appearance B. off its appearance C. by its appearance D. to its appearance 参考答案:C 答案解析:[解析] 本题是说慧星由于它的外观而显得与太阳系其他的天体不一样。distinguish from sb./sth.by sth.的意思是“由于……显得和……不同”。因此正确答案为C。