Windows not only let light in to cut downon electricity use for lighting, but thelight coming through the window also provides heat. However, windows are notsomething people typically associate with an advanced technology. Reseachersare now working on new technologies that enable a window to quickly change fromclear to dark and anything in between easily.
“It took us a long time to figure out whata window really is,”says Claes Granqvist. He’s a professor of solid-statephysics at Uppsala University in Sweden. “It 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 whenthey’re stuck indoors
Yet. windows are the weak link in abuilding when it comes to energy and temperature control. In winter cold airleaks in. When it’s hot and sunny, sunlight streams in. All of this sunlightcarries lots of heat and energy. And all of this extra heat forces people toturn on their conditioners. Producing blasts of cold air, which can feel so refreshing(使人清新的)，actually sucks up enormous amountsof electricity in buildings around the world.
Windows have been a major focus of energyresearch for a long time. Over the years, scientists have come up with a varietyof strategies for coating, glazing (用玻覆盖)，and layeringwindows to make them more energy efficient. Smart windows go a step further.They use chromogenic (发色的)technologies which involve changes of color.
Electrochromic (电致色的)windows use electricity tochange color. For example, a sheet of glass coated with thin layers of chemicalcompound such as tungsten oxide (氧化钨)works a bit like a batter. Tungsten oxides is clear when anelectric charge is applied and dark when the charge is removed, that is, whenthe amount of voltage(电压)is decreased, the window darkens until it’s completely dark afterall electricity is taken away. So applying a voltage determines whether thewindow looks clear or dark.
One important feature that makes a smartwindow so smart is that it has a sort of“memory”. All it takes is a small changeof voltage to turn the window from one state to the other. Then, it stays thatway. Transits take anywhere from in10 seconds to a few minutes, depending onthe size of the window. The development of smart windows could mean thatmassive air conditioning systems may no longer be needed. “In thefuture,”Granqvist says, “our buildings may look different.”
31. Which of the following of values ofwindows is NOT mentioned?
A. Theylet light in to brighten the house.
B. Theylet light in to heat the house.
C. Theylet us have visual contact with the surrounding world.
D. They let us think about the outside world.
32. The expression “when it comes to “ inParagraph 3 is used to
A. signalthe arrival of a guest.
B. indicatethe recovery of consciousness.
C. show our understanding of something.
D. introduce a new aspect of a topic.
33. According to Paragraph 4, smart windowsare the windows that
A. are coated.
B. are glazed.
C. have several layers.
D.can change color.
34. Whichparagraph gives an account of the way electrochromic windows……
A. Paragraphs 5.
35. Asmart window is smart mainly because
A. itcan change its size.
B. itcan change its structure.
C. itcan change the voltage of electricity.
D. it has a sort of memory.