完形填空: Electricity-Generating Tinted Windows Reveal a Sustainable Future Researchers have developed a new type of tinted "smart window" that generates electricity when darkened. The windows "can be __1__ converted into a solar cell to generate electricity for us," said Peidong Yang, a chemistry professor at UC Berkeley and researcher at Lawrence Berkeley National Laboratory, who __2__ the team responsible for the discovery. The new technology could potentially be used to __3__ everything from electric vehicles to skyscrapers. __4__ solar panels currently in use, the windows would be able to generate electricity and then send it to an inverter that changes that energy from a DC to an AC current. That __5__ could then be used to power the building or car that __6__ the windows. The smart windows are made from a __7__ called perovskite. When the crystal is heated, its internal structure rearranges to darken the color of the glass, allowing it to __8__ more light and create electricity. Scientists have known about the unique __9__ of perovskite for decades but have only learned to make use of them in the past five years. __10__ similar self-tinting windows on the market conserve energy passively by lowering the cost of air-conditioning, Yang’s innovation __11__ and reliably produces low amounts of electricity. Even after multiple transitions from light to dark, the smart windows are still able to produce electricity -- something other versions have largely __12__ to do. The team has already begun exploring the commercial potential of the product. There are several hurdles the team needs to jump through in order to transform the material from an idea to a __13__ product. To reach the goal, Yang insists a solar panel must be able to convert at least 10 percent of the sun’s rays to energy. The energy-generating windows from the Berkeley Lab remain __14__ after multiple cycles but haven’t been able to energize more than 7 percent of the sunlight they receive. Yang said __15__ this number will be a critical next step in the development process. 1. A. occasionally B. creatively C. automatically D. smartly 2. A. heads B. educates C. informs D. congratulates 3. A. test B. power C. stabilize D. build 4. A. Contrary to B. Instead of C. Apart from D. Similar to 5. A. current B. energy C. panel D. battery 6. A. houses B. connects C. energizes D. converts 7. A. tissue B. organism C. product D. mineral 8. A. reflect B.pass C. absorb D. shield 9. A. structures B. talents C. inventions D. properties 10. A. Since B. While C. Unless D. Even if 11. A. passively B. actively C. slowly D. merely 12. A. managed B. struggled C. refused D. neglected 13. A. sustainable B. reliable C. marketable D. unique 14. A. effective B. energetic C. smooth D. clear 15. A. lowering B. limiting C. caculating D. ra i sing