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.
The alarms will also include rising or falling frequencies to indicate whether people should go up__14__ down stairs. They were__15__ with the aid of a large grant from British Nuclear Fuels.
1. A) without B)with C)having D)selling
2. A) run by B)changed by C) decorated by D)criticized by
3. A) slow B)deaf C)blind D)lame
4. A) Alarms B) Alarm C) The alarm D) The alarms
5. A) noise B) sound C) music D) bell
6. A) watched B) produced C) learnt D) heard
7. A) where B) what C) that D) how
8. A) smoked B) smoke-filled C) filled with smoke D) smoke-filling
9. A) has taken B) takes C) took D) will take
10. A) on B) near C) without D) from
11. A) processes B) produces C) possesses D) proceeds
12. A) feature B) quality C)diagram D) source
13. A) basis on B) base on C) basing on D) based on
14. A) or B) and C) but D) otherwise
15. A) developed B) determined C) discovered D) delivered
key:BACDB DCBCC ADDAA