London, Reuters--What could annoy teenagers enough to make them stop hanging out with frie

London, Reuters--What could annoy teenagers enough to make them stop hanging out with friends and go home？
No, it's not a visit from their mothers, and not a threat to take away their cellphones or pocket money.
It's high-frequency noise. The UK police recently agreed to use a device (装置) called the Sonic Teenager Deterrent. It sends out a sound that makes teenagers become so impatient and angry that they have to cover their ears tightly and walk away.
The sound is at extreme high-pitch that can be heard by those under 20. The body's natural ability to detect some wave bands decreases almost entirely after 20, so few adults can hear the sounds. The black-box device, nicknamed the Mosquito because of its sound, can be fixed to the outside walls of shops, offices and homes. It sounds to youngsters like a crazy insect or a badly played violin. But it causes no physical damage.
A number of police forces and councils have given permission to use the system and want to install (安装) it at trouble spots.
Staffordshire Police Inspector Amanda Davies, who has given the device to shopkeepers in the Moorlands area, said, It is controlled by the shopkeepers--if they can see through their window that there is a problem, they turn the device on for a while until the group has run away.
【小题1】The device can be used to .A．threaten teenagers in publicB．drive away trouble-makers under 20C．help mothers control their teenage childrenD．help the police control shopkeepers【小题2】From the passage we can know that .A．young people often suffer from pains in earsB．shopkeepers are troubled by noisy insectsC．high-frequency noise is beyond the listening ability of people over 20D．the police invented a new device to deal with teenagers【小题3】The purpose of the writer to write the passage is .A．to advertise a new hi-tech deviceB．to tell the reader a piece of newsC．to sell the device to shopkeepersD．to inform the public as the spokesman of the police【小题4】Who will welcome the device most?A．Shopkeepers.B．The police.C．Young people.D．The producer.B

(答案→)B 解析：本文介绍了一种新型的装置，可以赶走在街头打架闹事的年轻人，而不会给成人带来麻烦。【小题1】细节题：从第三段的句子：It sends out a sound that makes teenagers become so impatient and angry that they have to cover their ears tightly and walk away.The sound is at extreme high-pitch that can be heard by those under 20.可知这种装置可以赶走20岁以下的年轻人。选B【小题2】细节题：从第二段的句子：The body's natural ability to detect some wave bands decreases almost entirely after 20,可知20岁以上的人听不见高频噪音。选C【小题3】主旨题：从第一句London, Reuters--What could annoy teenagers enough to make them stop hanging out with friends and go home？可知这是一则消息。选B【小题4】推理题：从最后一段的句子：It is controlled by the shopkeepers--if they can see through their window that there is a problem, they turn the device on for a while until the group has run away.可知店主最欢迎这种设备。选A

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