题干

如图所示,电源电压保持6V不变,电流表的量程为0﹣0.6A,电压表的量程为0﹣3V,定值电阻R1的规格为“10Ω 0.5A“,滑动变阻器R2的规格为“20Ω 1A”.现闭合开关S,为了保证电路及仪器的安全,在变阻器的滑片P移动的过程中,下列说法中正确的是(   )

A:电流表示数允许的电流变化范围为0.2A﹣0.5A

B:电阻R1消耗功率允许的变化范围为0.4W﹣0.9W

C:变阻器R2接入电路的阻值允许变化范围为2Ω﹣20Ω

D:电路消耗总功率允许的变化范围为1.2W﹣3W

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B

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    Everyone has two personalities(性格)-- one is showed to the world and the other is secret and real. You don't show your secret personality when you're awake because you can control(控制) yourself, but when you're asleep, your sleeping position shows the real you. And the important position that best shows your secret personality is when you go to sleep.

    If you go to sleep on your back, you're a very open person. You usually believe people and you are easily influenced(影响) by new ideas. You don't like to make people unhappy, so you never show your real feelings. You're quite shy and you aren't very confident(自信的).

    If you sleep on your stomach, you are a person who likes to keep secrets. You worry a lot and you're always easy to be sad. You never want to change your ideas, and you are pleased with your life. You usually live for today not for tomorrow.

    If you sleep on curled up(蜷缩),you are probably a very nervous person. You have a low opinion of yourself and often don't want to be hurt, so you are very defensive(有戒心的). You're shy and you don't like meeting people. You like to be alone.

    If you sleep on your side, you usually have a well-balanced(平衡的)personality. You know your strengths and weaknesses. You're usually careful. You have a confident personality. You sometimes feel worried, but you don't often get unhappy. You always say out what you think, even if it sometimes makes people angry.