第34题: [单项选择]{{B}}Questions 30 to 32 are based on the passage you have just heard.{{/B}} A. He knew this beforehand. B. He judged from his common sense. C. He judged from the speeds of sound D. He judged by reading the textbook. 参考答案:C 答案解析:[听力原文]
How did Ma Hua make such a judgement
[详解] Ma Hua在回答问题时,可以听到wave和electricity。C为正确答案。