题干

如图是某电子秤的原理图,人只要站在踏板上,仪表G就能显示人的体重,踏板下面的传感器R实质是一个阻值可随压力大小而变化的电阻,显示体重的仪表G实质是理想电流表,如果不计踏板的质量,电阻R随人的体重G变化的函数关系式为R=akGak是常量,GR的单位分别是N和Ω).下列说法正确的是(  )

A:传感器R是一个力电传感器

B:闭合电路测量时,电路中的电流随人的体重均匀变化

C:该秤零刻度线(即踏板空载时的刻度线)应标在电流表G刻度盘的零刻度处

D:如果要扩大电子秤的量程,滑动变阻器R′接入电路中的电阻应调大

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D

同类题1

课外精选美文阅读。

旧土

宁新路

    ①父亲把一堵旧墙拆了,和成泥巴,打成土坯,砌房子,抹墙皮二旧培的土看上去很老了,老的有点儿像姜黄色了,老人们说是唐朝的,甚至说是秦朝的.反正是久远留下来的墙,这墙的土跟地里的不一样,太陈旧了。

    ②我担心老成这样子的旧土,打成土坯,砌成房子,抹成墙皮,用不了多长时间,墙会像枯木一样,渐渐松散、倒掉。我劝父亲不要用这样的泥土砌墙、盖房,父亲一点儿也没理我的话,不但把那堵很长的大墙拆了,而且还把墙底下的土也挖出来和成了泥。我对父亲的做法很生气,理怨父亲,你用这么陈旧的泥土盖房子,心里到底有没有儿孙?父亲说,泥土有什么老不老的,泥土从来不会老;再老的泥土,见了水,和成泥,就是新泥;打成土坯,土坯就是新的;砌成墙,墙就是新的;盖成房子,房子就是新的,放心往吧……果然.这老墙的土,和成泥很耐用,打成土坯很硬实,砌成墙很敦实,抹上墙很诊酬贰。

    ③父亲的选择是对的。用旧土和泥巴砌成的培,比地里挖的新土有钻度.付风耐雨耐晒,这三十多年过去了,房子结结实实,院墙稳稳当当。父亲在这里住了二十多年,离去十多年了,如今他的子孙住着,墙皮旧了,墙体还是好好的,粉别了几次。还如新房似的。

    ④由此,我对旧土有了新的认识,我感到泥土是一种神奇、有生命而永远不死的物质。

    ⑤一块荒芜千万年的土地,看上去静静地沉睡在那里,甚至不长一草一木,你以为它早已死去,其实不然,如若浇上一瓢水,这喝了水的土,不管是黄土、红土、黑土,立刻就会变得灵动了起来,像睡醒了似的,黄土就会变得更黄,红土变得更红,黑土变得更黑—泥土活了。

    ⑥这喝了水被水唤醒了的旧土,你不动它,恍若永远在水中,它是醒着的;你若动它,它便会越来越有灵性。一旦被捏、揉、搅、捶、打过,泥就全醒了,倘若揉、搅、捶、打的时间更长,泥就会越鲜亮、越精神、越拈,甚至会灵气十足。这时候的泥好似有了筋有了骨,有了柔软轻盈的生命,打成土坯也好,烧成砖瓦陶瓷也好,就看你想让它成为什么,它就会让它的生命绽放出千姿百态的形状。

    ⑦一片毫无生机的土地,能给你的触发是枯涩的,你想象不出来这片寂寞的旧土,会长出什么来。它会长出金黄色的庄稼、香钳的苹果、参天的大树,变成碧波荡漾的林海吗?不需要你投入满地黄金,不需要你苦苦膜拜,只要你给它水,让它喝足了醒来,你撒下的种子,就会长出你要的东西。黄土高原荒凉,是泥土讨及那个地方吗,江南绿树成荫,是泥土偏爱那个地方吗?永远在等待种子和雨水。不论是黄土还是红土一等待的不是荒芜,是唤醒它的水。旧土永远在等待种子和雨水。

    ⑧那村边一望无际的田野,是什么时候成为耕田的?说明这片地耕种了几千年了。几千年来每年都春播秋收、地下挖出了秦朝的砖汉朝的瓦,还有唐朝的锄头,那它滋养了村里祖祖辈辈的人,还有那些牲口。耕种它的人,几千年来从这地里“冒”出来,死了又被理到这片地下。地被耕来耕去,人生生死死,这地几千年来有可能一年也没有闲过,会老了吗?我捧起这老田里的泥土。湿润润的,油黑黑的。孕育的小麦正在抽芽,哪像耕耘了几千年的土地,简直像年轻的母亲,正在哺育着孩子。我坚信,只要给它水的滋养给它足够的肥料,这田地的旧土,永远是年轻的,永远也不会老去。

    ⑨每一捧旧土,都不可小看。每一捧旧土,无不经受了数亿年的风霜雪雨,无不经受了数不清的践踏和摧残,无不见证、饱尝和承载了死的悲惨、血泪与世间残酷。被屠刀,被烈火,甚至被炮弹蹂猫过的泥土,喝过雨水,照样会活,照样会新,像新的泥土一样。这就是旧土。旧土承载世间万物,承受了天地间风雨雷电的摧残承受了人和动物的一切暴行,包含和消融了发生在大地上的所有污垢、但旧土不旧一旧土在一滴水的滋润下,依然是生机勃勃的精灵。丑陋和罪恶。尽管它是负重和苦难的,

    ⑩我膜拜大地,敬仰旧土。

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同类题2

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How to stay in a good mood

    It's typical to feel your mood starting to become bad. If you want to be able to stay in a good mood, then you have to form these habits that will keep you feeling happy.

    ⒈Don't take love for granted.

    If you're lucky enough to have a special someone, then you should make your time together meaningful. ____Make time to spend time with your special someone. Being around your loved one has been proven to make people happier.

    ⒉Get regular exercise.

    Regular exercise is one of the most important habits that you need to form ____ You can go running three times a week and walk the other four. Just make sure to be as active as you can every day.

    ⒊Spend time with your friends.

    ____Of course, don't always hang out with friends when you have a free moment. Make sure you do make time to see friends at least once or twice a week, if you can.

    ⒋Get enough sleep.

    ____ One of the easiest ways to stay in a good mood is to be well-rested. Waking up feeling full of energy will make you feel much more ready to face the day and much more excited about everything ahead of you.

    ⒌____

    If you want to stay in a good mood, then you have to make sure that you eat three healthy and diverse meals every day. Start off with a healthy breakfast, and don't skip this meal no matter what things happen. Have light snacks throughout the day, like yogurt or fruit, to keep you energetic.

A. Have a healthy eating schedule.

B. Make sure that you sleep for 7-8 hours a day.

C. Do begin with a healthy breakfast in the morning.

D. Hanging out with friends will keep you feeling alive

E. Don't stop doing the things you love with the person you love.

F. However, you don't have to do the same boring old thing every day.

G. Once you start exercising, do the same sports at the regular time every day.