题干

如果加在某定值电阻两端的电压从6V升高到10V,通过该电阻的电流变化了0.1A,则该电阻的电功率变化了(   )

A:1.6W

B:4.0W

C:0.4W

D:3.4W

上一题 下一题 0.0难度 选择题 更新时间:2011-10-18 07:39:50

答案(点此获取答案解析)

A

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    The kids in a village in Ethiopia wear dirty, ragged clothes. They sleep beside cows and sheep in huts made of sticks and mud. They have no school. Yet they all can chant the English alphabet, and some can make words.

    The key to their success: 20 tablet computers(平板电脑) dropped off in their Ethiopian village in February by a U.S. group called One Laptop Per Child.

The goal is to find out whether kids using today's new technology can teach themselves to read in places where there are no schools or teachers. The Massachusetts Institute of Technology researchers analyzing the project data say they're already amazed. “What I think has already happened is that the kids have already learned more than they would have in one year of kindergarten,” said Matt Keller, who runs the Ethiopia program.

    The fastest learner—and the first to turn on one of the tablets—is 8-year-old Kelbesa Negusse. The device's camera was disabled to save memory, yet within weeks Kelbesa had figured out its workings and made the camera work. He called himself a lion, a marker of accomplishment in Ethiopia.

With his tablet, Kelbasa rearranged the letters HSROE into one of the many English animal names he knows. Then he spelled words on his own. “Seven months ago he didn't know any English. That's unbelievable,” said Keller.

    The project aims to get kids to a stage called “deep reading,” where they can read to learn. It won't be in Amharic, Ethiopia's first language, but in English, which is widely seen as the ticket to higher paying jobs.

同类题4

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