第4题: [单项选择]Passage Two Questions 29 to 31 are based on the passage you have just heard.A) They were driven by steam engines. C) They were pulled by riders themselves. B) They were pulled by animals or humans. D) There were totally unusable. 参考答案:B 答案解析:[听力原文] Which of the following is true of early elevators
第5题: [单项选择]下述哪种心脏病不是由风湿病引起的 A. 二尖瓣狭窄 B. 二尖瓣关闭不全 C. 缩窄性心包炎 D. 高血压性心脏病 E. 主动脉瓣狭窄 参考答案:D 答案解析:风湿病可以引起二尖瓣狭窄、关闭不全等,但不是高血压性心脏病的病因。