如图所示，直线AOC为某一电源的总功率P总随电流i变化的图线，抛_爱下问搜题

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问题填空题

如图所示，直线AOC为某一电源的总功率P_总随电流i变化的图线，抛物线OBC为同一直流电源内部热功率P_r随电流I变化的图象．若A、B对应的横坐标为2A，那么线段AB表示的功率为____________及I=2A时对应的外电阻是_______________．

答案

2W，0．5Ω

从图像中可知当I=3A时，电源的总功率为9W，电源内部热功率为9W，所以根据公式P_总=EI可得E=3V，根据公式，r=1故当I=2A时电源的总功率为P_总=6W，P_r=4W，所以AB表示的功率为P_总-P_r=2W，即外电阻消耗的功率为2W，根据公式可得R=0．5Ω

解答题

我们班有男生19人，女生17人，平均分成6个小组，每个小组多少人？

完形填空

完形填空（共20小题；每小题1。5分，满分30分）
阅读下面短文，掌握其大意，然后从36—55各题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。
When I was a teenager, my dad did everything he could do to advise me against becoming a brewer (造酒人). He’d   36  his life brewing beer for local breweries only to make a living, 37   had his father and grandfather before him. He didn’t want me   38  near a vat (酿酒用的桶) of beer. So I did as he asked. I got good   39 , went to Harvard and in 1971 was accepted into a graduate program there that   40  me to study law and business at the same time.
In my second year of graduate school, I began to realize that I’d   41  done anything but go to school. So, at 24 I decided to drop out.   42 , my parents didn’t think this was a great idea. But I felt strongly that you can’t   43  till you’re 65 to do what you want in life.
I packed my stuff into a bus and headed for Colorado to become an instructor at Outward Bound. Three years later, I was ready to go back to   44 . I finished Harvard and got a highly-paid job at the Boston Consulting Group Still, after working there five years, I   45 , “Is this what I want to be doing when I’m 50?” At that time, Americans spent good money on beer in   46   quality. Why not make good beer for   47 ? I thought.
I decided to give up my job to become   48 . When I told Dad, he was   49 , but in the end he   50  me. I called my beer Samuel Adams,   51  the brewer and patriot (爱国者) who helped to start the Boston Tea Party.   52  I sold the beer direct to beer drinkers to get the   53  out. Six weeks later, at the Great American Beer Festival, Sam Adams Boston Lager (淡啤酒) won the top prize for American beer. In the end I was destined (注定) to be a brewer. My   54  to the young is simple: Life is very   55 , so don’t rush to make decisions. Life doesn’t let you plan.

A．anywhere、

A．Fortunately

D．Surprisingly

D．my decision

C．an instructor

D．an engineer