试题与答案

小灯泡L的额定电压为6V,小明通过实验测得其电流随电压变化的曲线如图.由图可知,

题型:填空题

题目:

小灯泡L的额定电压为6V,小明通过实验测得其电流随电压变化的曲线如图.由图可知,灯泡两端电压增大时,通过灯丝的电流增大,灯丝电阻______(增大、不变、减小).当L正常发光时,通过灯丝的电流是______A,此时灯丝的电阻为______Ω;通过调节滑动变阻器,使小灯泡两端的电压为3V,则此时小灯泡消耗的实际功率为______W.

答案:

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题型:阅读理解

阅读理解。

     Until late in the 20th century, most Americans spent time with people of different generations. Now middle-

aged Americans may not keep in touch with old people until they are old themselves.

     That's because we group people by age. We put our three-year-olds together in day-care centers, our 13-

year-olds in schools and sports activities, and our 80-year-olds in senior citizen homes. Why?

     We live away from the old for many reasons. Young people sometimes avoid the old to get rid of fears of

aging and dying. It is much harder to watch someone we love disappear before our eyes. Sometimes it's so

hard that we stay away from the people who need us the most.

     Fortunately, some of us have found our way to the old. And we have discovered that they often save the

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     A reporter moved her family onto a block filled with old people. At first her children were disappointed. But

the reporter baked banana bread for the neighbors and had her children deliver it and visit. Soon the children

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lonely," the reporter said.

     The young, in turn, save the old. Once I was in a rest home when a visitor showed up with a baby, she was

immediately surrounded. People who hadn't gotten out of bed in a week suddenly were ringing for a wheelchair.

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and cure. Grandparents are a special case. They give their grandchildren a feeling of security and continuity. As

my husband put it, "My grandparents gave me a deep sense that things would turn out right in the end."

     Grandchildren speak of attention they don't get from worried parents. "My parents were always telling me

to hurry up, and my grandparents told me to slow down," one friend said. A teacher told me she can tell which

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1. Now in an American family, people can find that _____. [ ]

A. children never live with their parents

B. not all working people live with their parents

C. aged people are supported by their grandchildren

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A. the old don't like to live in a big family

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A. old people in America lead a hard life

B. old people in America enjoy banana bread

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D. old people are easy to get along with

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A. they had never seen a baby before

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D. the baby's mother would take care of them

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A. Because they have relationships with their grandparents.

B. Because their worried parents ask them to act like that.

C. Because they have nothing to worry about.

D. Because their teachers ask them to act like that.

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题型:单项选择题

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