题干

某同学做“探究功与速度变化的关系”的实验,如图所示,小车在一条橡皮筋的作用下弹出沿木板滑行,这时橡皮筋对小车做的功为W.当用2条、3条…实验时,使每次实验中橡皮筋伸长的长度都保持一致,每次实验中小车获得的速度都由打点计时器所打的纸带测出.

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同类题1

阅读课内语段,回答后面问题。

    ①暖国的雨,向来没有变过冰冷的坚硬的灿烂的雪花。博识的人们觉得他单调,他自己也以为不幸否耶?江南的雪,可是滋润美艳之至了;那是还在隐约着的青春的消息,是极壮健的处子的皮肤。雪野中有血红的宝珠山茶,白中隐青的单瓣梅花,深黄的磬口的蜡梅花;雪下面还有冷绿的杂草。胡蝶确乎没有;蜜蜂是否来采山茶花和梅花的蜜,我可记不真切了。但我的眼前仿佛看见冬花开在雪野中,有许多蜜蜂们忙碌地 l飞着,也听得他们嗡嗡地闹着。

    ②孩子们呵着冻得通红,像紫芽姜一般的小手,七八个一齐来塑雪罗汉。因为不成功,谁的父亲也来帮忙了。罗汉就塑得比孩子们高得多,虽然不过是上小下大的一堆,终于分不清是壶卢还是罗汉;然而很洁白,很明艳,以自身的滋润相粘结,整个地闪闪地生光。孩子们用龙眼核给他做眼珠,又从谁的母亲的脂粉奁中偷得胭脂来涂在嘴唇上。这回确是一个大阿罗汉了。他也就目光灼灼地嘴唇通红地坐在雪地里。

    ③第二天还有几个孩子来访问他;对了他拍手,点头,嘻笑。但他终于独自坐着了。晴天又来消释他的皮肤,寒夜叉使他结一层冰,化作不透明的水晶模样;连续的晴天又使他成为不知道算什么,而嘴上的胭脂也褪尽了。

    ④但是,朔方的雪花在纷飞之后,却永远如粉,如沙,他们决不粘连,撒在屋上,地上,枯草上,就是这样。屋上的雪是早已就有消化了的,因为屋里居人的火的温热。别的,在晴天之下,旋风忽来,便蓬勃地奋飞,在日光中灿灿地生光,如包藏火焰的大雾,旋转而且升腾,弥漫太空,使太空旋转而且升腾地闪烁。

    ⑤在无边的旷野上,在凛冽的天宇下,闪闪地旋转升腾着的是雨的精魂……

    ⑥是的,那是孤独的雪,是死掉的雨,是雨的精魂。

同类题2

阅读下列短文,从文后各题所给的四个选项中选出一个最佳答案。

    There was a blind girl who hated herself because she was blind. In fact, she 1 nobody except her boyfriend, for he was always 2 to help her. She used to tell her boyfriend,“If I could see the 3, I would marry you.”

    One day, someone donated (捐赠) a pair of  4 to her. When the bandages (绷带) came off, she was able to see everything, including her boyfriend, for the 5time. He asked her, "Now that you can see the world, will you  6  me?" The girl looked at her boyfriend and was greatly surprised to see that he was  7. She had never expected that. She would not like to be with a blind husband for the rest of her life, so she 8to marry him.

     Her boyfriend left in tears and a few days later wrote a 9 to her, saying, "My dear, take good care of your eyes. 10 they are yours. They were mine."

     This is how the human brain (人脑) often works when our status (地位) changes. Only a very few remember what  11 was like before. And we often ask for more than we need. Life is a gift. Today, before you complain about the 12  of your food, think of someone who has nothing to 13. Before you complain about life, think of someone who went to heaven (天堂) too early. Before you complain about your old 14, think of the people who are living in the streets. And when you are tired and complain about your job, think of those who have no jobs. So 15  what you have and don't forget your past.