閱讀下面的短文。短文中有 15個(gè)空白，在文章的后面，每一個(gè)空白都列了 4個(gè)備選答案。請(qǐng)根據(jù)文章的內(nèi)容選擇合適的詞或短語(yǔ)填在空白處。

　　Singing Alarms Could Save the Blind

　　If you cannot see, you may not be able to1 find your way out of a burning building — and that could be fatal. A company in Leeds could change all that2 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 where 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,” she 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 of3 a large 8 room. It 9 them nearly four 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 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.

詞匯： directional /di5rekFEnEl/ adj. 定向的 thermal-imaging熱效應(yīng)成像 exit /5eksit/ n. 出口 pinpoint /5pin7pCint/ v. 精確地確定 install /in5stC:l/ v. 安裝 concept /5kCnsept/ n. 概念，觀念 residential /7rezi5denFEl/ adj. 居住的 emergency /i5mE:dVnsi/ n.緊急情況 static /5stAtik/ n. 靜電噪音 grant /^rB:nt/ n. 授予物，準(zhǔn)許potential /pE5tenF(E)l/ n. 潛力 注釋：

　　1.在謂語(yǔ)動(dòng)詞中，不能并列使用兩個(gè)情態(tài)動(dòng)詞，如 may和 can就不能并列使用。如果由于表達(dá)需要，要同時(shí)用“可能”和“能夠”，就得說(shuō)(寫)成 may be able to。 I may be may be able to come tomorrow, but 1 cannot promise. 我可能明天來(lái)，但我不可能作出承諾。 2. that指第一句所表達(dá)的意思。
　3. … find their way out of…：意為“找到從……出去的路”。練習(xí)：

　　1. A without B with C having D selling

　　2A 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 on B and C but D otherwise

　　15. A developed B determined C discovered D delivered