第27题: [单项选择]Questions 22 to 25 are based on the conversation you have just heard.A. How to care for precious metal. B. A standard unit for measuring weight. C. The value of precious metals. D. Using the metric system. 参考答案:B 答案解析:[解析] 22-25 W: Dr. Thomas This is Keet Bradley from the Daily News. (22) I’d like to ask you s