题干

某兴趣小组为了研究电子温控装置,将热敏电阻R1(热敏电阻的阻值随温度的升高而减小)、定值电阻R2以及电压表和电流表连入如图所示电路,电源电压不变.闭合开关S,当温度升高时,下列说法正确的是(   )

A:电流表和电压表示数均变小

B:电压表V与电流表A示数之比变小

C:电流表示数变小,电压表示数变大

D:电路消耗的总功率变大

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答案(点此获取答案解析)

D

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阅读理解

    The police in Taiwan are unable to judge whether to treat it as an extremely clever act of stealing or an even cleverer cheat. Either way, it could be the perfect crime, because the criminals are birds — homing pigeons!

    The crime begins with a telephone message to the owner of a stolen car: if you want the car back, pay up. Then, the car owner is directed to a park, told where to find a bird cage and how to attach money to the neck of the pigeon inside. Carrying the money in a tiny bag, the pigeon flies off.

    There have been at least four such pigeon pick-ups in Changwa. What at first seemed like the work of a clever stay-at-home car thief, however, may in fact be the work of an even lazier and more inventive criminal mind — one that avoids not only collecting money but going out to steal the car in the first place. Police officer Chen says that the criminal probably has pulled a double trick: he gets money for things he cannot possibly return. Instead of stealing cars, he lets someone else do it and then waits for the car-owner to place an ad in the newspaper asking for help.

    The theory is supported by the fact that, so far, none of the stolen cars have been returned. Also, the amount of money demanded — under 3,000 Taiwanese dollars — seems too little for a car worth many times more.

    Demands for pigeon-delivered money stopped as soon as the press reported the story. And even if they start again, Chen holds little hope of catching the criminal. “We have more important things to do,” he said.