Smart Window It took us a long time to figure out what a window really is, says Claes Granqvist. Hes a professor of solid-state physics at Uppsala University in Sweden3. Its contact with the outside world. You have to have visual contact with the surrounding world to feel well. So, windows and natural light are important for improving the way people feel when theyre stuck indoors. Windows have been a major focus of energy research for a long time. Over the years, scientists have come up with a variety of strategies for coating, glazing, and layering windows to make them more energy efficient. Smart windows go a step further. They use chromogenic technologies which involve changes of color. One important feature that makes a smart window so smart is that it has a sort of memory. All it takes is a small jolt of voltage to turn the window from one state to the other. Then, it stays that way. Transitions take anywhere from 10 seconds to a few minutes, depending on the size of the window. The development of smart windows could mean that massive air conditioning systems may no longer need. In the future, Granqvist says, our buildings may look different. flip n. v. 用手指轻弹，轻击tungsten oxide 氧化钨 refreshing adj. 使人清爽的electrochromic adj. 电致变色的 chromogenic adj. 发色的air conditioning 空调，空调系统 1. cutting edge ： 本意为：刃口, 刀刃;比喻意为：最先进的，科技含量最高的。 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。 1. Which of the following statements does not indicate the importance of windows as described in the first two paragraphs? B) Windows help to save energy by letting light in. D) Windows enable people to have contact with the outside world. A) In the cold winter. C) When air conditioners are turned on. 3. What are smart windows, according to Paragraph 4? B) Windows that are glazed. D) Windows that have many layers. A) Electricity. C) A battery.