Conversation Two
W: Dr. Thomas? This is Keet Bradley from the Daily News. [22]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. What would you like to know?
W: First of all, how was the standard weight used?
M: Well, [23]people in our department use it to check the scales all over the country. The department of weights and measures, we are a government agency. It's our responsibility [23]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 that we used to use. It had to be replaced because it was imprecise. [24]You see it was made of poor quality metal that 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 45,000 dollars.
W: 45,000 dollars? For a one kilogram weight? That's more expensive than gold. Is it really worth that much?
M: [25]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.

Questions 22 to 25 are based on the conversation you have just heard.
22. What is the conversation mainly about?
正确答案：B
解析：女士说：“我想问您一些关于您买的官方标准砝码的问题。”直接进入话题，故B正确。所有选项都是类似于名词词组的表达，可以判断出题目是主旨题。
23. How is the new weight used?
正确答案：A
解析：男士说：“我们部门的人用它来检查全国的（重量）计量器……确保所有的（重量）计量器都能准确地测量一公斤……”。故答案为A。四个选项都是动词不定式结构，多表示目的（用途）、打算或将来的动作。根据选项内容可以判断题目询问某物的用途。对话中还有提示，在听到问题“how was the standard weight used”时，要注意问题的回答。
24. Why is it necessary to replace the old standard weight?
正确答案：C
解析：男士说：“你知道它是由容易渗水的劣质金属制成的。”故答案为C。前面三个选项都有it，描述的都是it无法再使用的原因，故可基本推断出问题。注意“听到什么选什么”。
25. What does the man probably think about the cost of the new weight?
正确答案：D
解析：男士说：“我肯定（物有所值）。所有产业都依靠我们政府机构来监控他们的（重量）计量器，从而当他们买卖产品时能有一个（重量）标准。”故D正确。根据选项的提示词small, value, reasonable和high，可猜测题目是问对某物价值的评价。“I'm sure it is”是省略句，省略worth it，说明男士认为这个价钱物有所值。