It used to take Redwood City,California police hours to locate gunfire．Now,they have a new tool that helps them find the gunfire quickly．This new tool is called the Shot Spotter,The police began using the Shot Spotter in 1995．They wanted to cut down on gunfire in their city. One Shot Spotter covers a square mile．Eight microphones are put on the roofs of buildings．These microphones pick up gunfire noise．It only takes seven seconds to report the gunfire to the police．Then a red dot on the police map shows where the action is. The Shot Spotter really works well．It locates the gunfire within 20 to 40 feet plus or minus．Redwood City police are very happy with the Shot Spotter．They think it might have helped catch the D. C．sniper. Shot Spotters cost a lot of money．One of them sells for$200,000．Despite the cost,Shot Spotters can be a big help in fighting crime. The Shot Spotter has helped police__.

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rency used in each country. Help each person to choose the proper currency.(下面是一些国家的货币缩写，请帮助每个人选择正确的货币。货币用字母A---E表示。）A. CNY It’s the official currency(货币) of China. It is only used in China.B. USD It’s the official currency of the United States. It is widely used in the US.C. EUR It’s just used in some EU members: Belgium, Finland, Germany, Greece, Ireland, Italy, Spain etc.D. RUB It’s the currency of the Russian Federation. It is used in Russia.E. JPY Yen is the currency used in Japan. It is on

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to take

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问答题

It is ﹍ to believe that AI programs have the power to take over the world.

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单选题

This river used to ______ a terrible smell, but now it is clear and clean.

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单选题

Take a coat along; it’s ___ to be cold down there.

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