题目内容：
Singing Alarms Could Save the BlindIf 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____ (1) all that with directional(定向的)sound alarms capable of guiding you to the exit.
Sound Alert, a company run____ (2) the University of Leeds, is installing the alarms in a residential home for____ (3) people in Somerset and a resource center for the blind in Cambridge．The alarms produce a ____ (4) range of frequencies(频率)that enable the brain to____ (5) where the sound is coming from.
Deborah Whittington 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(白噪声)that people say sounds like static on the radio," she says．"Its life-saving potential is____ (7)."She conducted an experiment in which people were filmed by thermal-imaging(热效应成像)cameras trying to find their____ (8) out of a large smoke-filled room．It____ (9)them nearly four minutes to find the door without a sound alarm, ____ (10) only 15 seconds with one.
Whittington studies how the brain ____ (11) sounds at the university．She says that the____ (12) of a wide band of frequencies can be pinpointed(精确的确定)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 failing frequencies to____ (14) whether people should go up or down stairs．They were____ (15) with the aid of a large grant(拨款)from British Nuclear Fuels. A．change
B．cure
C．demand
D．set
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