注释：
1. cutting edge：本意为：(刀片的)刃口, 刀刃；比喻意为：最先进的，科技含量最高的。
2. anywhere in between with a flip of a switch：就在开或关的一霎那。
3. Uppsala University in Sweden：瑞典的乌普萨拉大学。乌普萨拉是瑞典东部一座城市，位于斯德哥尔摩的西北方向。
练习：
1. Which of the following statements does not indicate the importance of windows as described in the first two paragraphs?
A) Windows can change from clear to dark to save energy.
B) Windows help to save energy by letting light in.
C) Windows help to save energy by providing heat.
D) Windows enable people to have contact with the outside world.
2. When are windows the weak link in a building?
A) In the cold winter.
B) In the hot summer.
C) When air conditioners are turned on.
D) Both A and B.
3. What are smart windows, according to Paragraph 4?
A) Windows that are coated.
B) Windows that are glazed.
C) Windows the color of which can be changed.
D) Windows that have many layers.
4. To make electrochromic windows change color, what is applied to the window glass?
A) Electricity.
B) Tungsten oxide.
C) A battery.
D) A voltage.
5. What will be the benefit if the research on smart windows turns out to be successful, according to the last paragraph?
A) The buildings will look different.
B) Windows can be as large as you want.
C) We may not need air conditioners any more.
D) They are less expensive than traditional windows.
答案与题解：
1. A 第一段告诉我们窗户因为让阳光进入房间，并且为房间提供热源，所以节约了能源。第二段说，窗户使人们能接触外部世界。所以B、C和D都说明了窗户的重要性。第一段最后一句说，研究者正在实验能让窗户变换亮度，但并没有说已经实验成功，所以A是错误的说法，是正确选择。
2. D 短文第三段的第一句说：windows are the weak link in a building，接下来是对这句话分寒冬和炎夏做了说明。所以D是正确选择。
3. C 第四段告诉我们，多年来，科学家已研究出多种通过窗户节能的办法，而smart windows使用的技术使窗户能变换颜色。所以C是正确选择。
4. B 第五段第二句提供了答案。a sheet of glass coated with thin layers of chemical compound such as tungsten oxide中的 coated是“涂上一层薄薄的．．．”的意思。
5. C 短文最后一段的第五句提供了答案。
