单选题Questions 7 to 10 are based on the following conversation. At the end of the conversation, you will be given 20 seconds to answer the questions. Now, listen to the conversation.
单选题
What is the conversation mainly about? A. How to care for precious metals. B. A standard unit for measuring weight. C. The value of precious metals. D. Using the metric system.
【正确答案】
B
【答案解析】[解析] 7-10 W: Dr. Smith? This is Jennifer Williamson from the Daily News. [7]I'd like to ask you some questions about the new official standard weight that you purchased. M: I'd be happy to help you. W: First of all, how is the standard weight used? M: Well, [8]we use it to check the scales all over the country. Our department of weights and measures is a government agency. It's our responsibility to see that all the scales measure a kilogram accurately. So this is the way we use to adjust the scales. W: How did you check the scales before? M: We have an old standard weight. [9]It had to be replaced because it was imprecise. You see it was made of poor quality metal that was too porous. It absorbed too much moisture. W: Oh. So when the weather was humid it weighed more and when it was dry it weighed less. M: Exactly. And that variation can affect the standards of the whole country. So our department had the new weight made out of higher quality metal. W: How much did it cost? M: About 45 thousand dollars. W: 45,000 dollars? For one kilogram weight? That's more expensive than gold. [10]Is it really worth that much? M: [10]I'm sure it is. Industries depend on our government agency to monitor the accuracy of scales. So that when they buy and sell their products there is one standard. Think of the drug industry, for example, those companies rely on high accuracy scales to manufacture and package medicine.
[解析] 对话开始女士做了自我介绍后，便点明话题：new offcial standard weight that you purchased，由此可以确定他们在谈论关于选项B中的“衡量重量的标准单位”。 [点睛] 主旨大意题。解答这类题要非常注意对话发生的情景，因为上下文之间会多次出现同一范围的词句，这些词句将会给我们很大的启示，并帮助我们快速地找到正确选项。本段对话中，两人多次在问答中用到如weight，measure，scale这类的词，于是正确选项也就比较明显了。
单选题
How is the weight used? A. To check the accuracy of scales. B. To calculate the density of other metals. C. To observe changes in the atmosphere. D. To measure amounts of rainfall.
【正确答案】
A
【答案解析】[解析] 女士问及标准秤如何使用，Dr．Smith回答：“用来检查全国的秤……”由此便可得出答案为A。 [点睛] 事实细节题。这类题的正确答案通常用同义表达对原句进行改写，有些甚至照搬原句。对话最后Dr．Smith也提到了monitor the accuracy of scales，由此也可以得出答案。
单选题
It was necessary to replace the old standard weight because A. someone spilled water on it. B. someone lost it. C. it was made of low quality metal. D. the standard for measuring had changed.
【正确答案】
C
【答案解析】[解析] 对话中出现了poor quality metal这样的词句来形容old standard weight，那也就是说老标准秤的质量不理想，由此可知老标准秤需更换的原因是选项C。 [点睛] 事实细节题。本题询问原因，因此需弄清对话中的因果逻辑关系。更换老秤的主要原因是因为所使用的金属品质较低，所以才造成受天气湿度的影响。
单选题
What does Dr. Smith probably think about the cost of the new weight? A. It is a small amount to pay for so much precious metal. B. It is difficult to judge the value of such an object. C. It is reasonable for an object with such an important function. D. It is too high for such a light weight.
【正确答案】
C
【答案解析】[解析] 女士觉得新标准秤的价格more expensive than gold，询问Dr．Smith是否物有所值，Dr．Smith回答说：“我相信是的。”而后，又举出医药行业的例子来支持他的观点，所以，C项成为正确答案是有根据的。 [点睛] 推理判断题。题目询问Dr．Smith对新秤价格的看法。这类题常常要求我们根据说话人的话语做出合理的推断，因此对相关细节需留意。