第23题: [单项选择]Passage Three Questions 33 to 35 are based on the passage you have just heard. A. In the lower atmosphere. B. In the upper atmosphere. C. On the Earth. D. Near the Earth. 参考答案:B 答案解析:[听力原文] 33-35 Ozone is a form of oxygen. It is found in the air we breathe and in the upper at