题干

某课外兴趣小组测量一个标有“12V”字样,功率未知的灯泡灯丝电阻R随灯泡两端电压U变化的关系,得到如图所示的图线,则由此可以得到:

①在正常发光情况下,灯泡的电功率P=____W.

②若一定值电阻与该灯泡串联,接在20V的电压上,灯泡能正常发光,则串联电阻的阻值为____Ω.

③若用电动势为12V的理想电源给小灯泡供电,当灯泡开关合上后,需0.1s灯泡才能达到正常亮度,这0.1s内流过灯泡的电流变化情况是由大变小,最大电流是____A.

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24,4,12

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B

    I first met Paul Newman in 1968, when George Roy Hill, the director of Butch Cassidy and the Sundance Kid, introduced us in New York City. When the studio didn't want me for the film— it wanted somebody as well known as Paul— he stood up for me. I don't know how many people would have done that; they would have listened to their agents or the studio powers.

    The friendship that grew out of the experience of making that film and The Sting four years later had its root in the fact that although there was an age difference, we both came from a tradition of theater and live TV. We were respectful of craft(技艺)and focused on digging into the characters we were going to play. Both of us had the qualities and virtues that are typical of American actors: humorous, aggressive, and making fun of each other— but always with an underlying affection. Those were also at the core (核心)of our relationship off the screen.

    We shared the brief that if you're fortunate enough to have success, you should put something back— he with his Newman's Own food and his Hole in the Wall camps for kids who are seriously ill, and me with Sundance and the institute and the festival. Paul and I didn't see each other all that regularly, but sharing that brought us together. We supported each other financially and by showing up at events.

    I last saw him a few months ago. He'd been in  and out of the hospital.He and I both knew what the deal was,and we didn't talk about it. Ours was a relationship that didn't need a lot of words.