题干

一个子弹质量为10g、以800m/s的速度飞行;一位运动员质量为60kg、以10m/s的速度奔跑。两者相比

A:子弹的动能较大

B:运动员的动能较大

C:二者的动能一样大

D:无法比较它们的动能

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答案(点此获取答案解析)

A

同类题1

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    A few years ago, I took a sightseeing trip to Washington, DC. I saw many of our nation's treasures, and I also saw a lot of our fellow citizens on the street —1 ones, like beggars(乞丐)and homeless folks.

    Standing outside the Ronald Reagan Center, I heard a voice saying: “Can you help me?” When I2, I saw an elderly blind woman with her hand 3. In a natural reaction, I 4 into my pocket, pulled out all of my loose change and placed it in her hand without even looking at her. I was 5 at being bothered by a beggar.

    But the blind woman smiled and said: “I don't want your money. I just need help finding the6.”

    In an instant, I realized what I had done. I had acted with prejudice(偏见)— I'd 7 another person8for what I believed she had to be.

    I hated what I saw in myself. This incident brought back my basic belief. It 9 me that I believed in being modest even though I'd lost that 10 for a moment.

    The thing I had forgotten about myself is that I am a (n)11. I left Honduras and arrived in the U. S. at the age of 15. I started my new life with two suitcases, my brother and sister, and a strong mother. Through the 12, I have been a dish washer, roofer, mechanic, cashier and pizza delivery driver 13 many other humble hobs, and14 I became a network engineer.

    In my own life, I have15 many acts of prejudice. I remember a time, at the age of 17 — when I was a busboy, I heard a father tell his little boy that if he did not do well on school, he would 16 like me. I have also seen the same treatment of family and friends, so I know what it's like, and I should have known 17.

    But now, living my American middle class lifestyle, it is too easy to forget my past, to forget who I am and where I have been, and to lost sight of where I want to go. That blind woman cured me of my18. She reminded me of my belief in being humble, and to always keep my eyes and heart open.

    19, I helped that woman to the post office. And in writing this essay, I hope to thank her for the20 lesson she gave me.

同类题2

阅读下面语段,完成下面题目。
        ①1082年,苏东坡途中遇雨,没带雨具,常人在此情况下只有“狼狈”二字,雨点打在竹林发出巨响,不是不寒心的。好一个苏轼,就这样写下宋词中我最爱:
        ②“莫听穿林打叶声,何妨吟且徐行。”
        ③不用“不听”,而用“莫听”。意志力,跟雨声抗衡;莫听,是你可以选择听,但声音也只是外物,你的心可以决定听不到。听不到,着一“莫”字,境界就从容自主起来。
        ④“何妨吟啸”,那“何妨”也是一派优游,反正变成落汤鸡的现实无法改变,倒不如吟起当时流行曲。无法改变的事情,就让它自然存在吧。
        ⑤苏老当时只拿着竹拐杖,穿《倩女幽魂》里的那种草鞋,从头到脚尽湿,没有骑马,真是一步似一生。但他说:“竹杖芒鞋轻胜马,谁怕”?从负面自嘲发出乐趣,雨中持杖,穿轻便草鞋,比骑马还轻便。
        ⑥雨停了,“金句”来了。
        ⑦“回首向来萧处,归去,也无风雨也无晴。”境界非常较低的是,好了,雨停了,身干了,雨后自有晴天,人无须在逆境中慌张。
        ⑧苏东坡却更通透无碍,雨可以不是雨,逆境中凭心境自乐,于是,晴天也不是晴天,万法无常之变与他的心境无关。
        ⑨我常常想,万一因时运低而见鬼,也会学苏老,心里无鬼,于是,看不见,看不见,然后转身走开,吟啸:“也无风雨也无晴。”
        ⑩这七个字的境界,值得我们在无常变化的处境中用来做口头