第26题: [单项选择]The primary purpose of paragraph I is to ______. A. summarize past research and introduce a new study B. describe a historical period C. emphasize the advantages of one theory over another D. define a term and illustrate it with an example 参考答案:D 答案解析:第一段的主要内容就是提出观点,给出定义,然后举例加以证明。