第20题: [单项选择]It is implied in the passage that most drugs can be ______. A. manufactured artificially B. got from animal sources C. found naturally in plants D. made from tree bark 参考答案:A 答案解析:[分析] 本题为推理题。A项“大多数药物可人工制成”与第四段第二句话“但多数现代药物是科学家研制出来的化学混合物”意思相吻合,故应为答案。其他选项似乎对,但细琢磨,均与题干中“大多数”一词不符,故排除
第29题: [单项选择]What is the woman’s reply A. She knows Professor Arnold has come. B. She thinks Professor Arnold has checked in. C. She is sure that Professor Arnold bas arrived. D. She doesn’t know whether Professor Arnold has arrived. 参考答案:D 答案解析:[听力原文] M: Has Professor Arnold from Sydney University arrived W: I’ll have to check. Then I’l