完形填空 阅读下面的短文,文中有15处空白,每处空白给出了4个选项,请根据短文的内容从4个选项中选择1个最佳答案。 Deborah Withington of Sound Alert If you cannot see, you may not be able to find your way out of a burning building-and that could be fatal. A company in Leeds could change all that__1__ directional sound alarms capable of guiding you to the exit. Sound Alert, a company__2__ the University of Leeds, is installing the alarms in a residential home for__3__ people in Sommerset and a resource centre for the blind in Cumbria.__4__produce a wide range of frequencies that enable the brain to determine the __5__ is coming from. Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be __6__ by humans. It is a burst of white noise__7__ people say sounds like static on the radio, he says. Its life-saving potential is great She conducted an experiment in which people were filmed by thermal-imaging cameras trying to find their way out of a large__8__ room. It__9__ them nearly our minutes to find the door__10__ a sound alarm, but only 15 seconds with one. Withington studies how the brain__11__ sounds at the university. She says that the __12__ of a wide band of frequencies can be pinpointed more easily than the source of a narrow band. Alarms__13__ on the same concept have already been installed on emergency vehicles. |