题干

下图所示的情景中,关于力对物体做功的叙述,正确的是()

A:大理石表演拉汽车潜行,此时人拉车做的功

B:起重机吊着重物水平移动,钢丝绳的拉力对重物做的功

C:举重运动员举着杠杆不动,运动员对杠杆做的功

D:足球在水平地面上滚动,足球的重力对足球做的功

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答案(点此获取答案解析)

A

同类题2

阅读下面的选文,回答下列各题。

一个婴儿的拥抱

    ①我们是餐馆里唯一带孩子就餐的顾客,我把伊瑞克放进一把高高的婴儿椅里。突然,伊瑞克高兴地尖叫起来:“嗨,嗨……”并兴奋地用手拍打着椅把。当伊瑞克高兴地咯咯笑着扭动身体时,他的眼睛笑得起了皱纹,嘴巴咧开着,露出了没牙的牙床。我环顾四周,找到了让他快乐的根源。那是一个穿着肥大裤子的老头,脚趾头从鞋子里戳出来,衬衫很脏。我们离他比较远,但我相信他身上一定很臭。

    ②那个老头的手挥舞着,“嗨,我看见你了,小家伙。”我和丈夫交换了一下眼神,“我们该怎么办?”伊瑞克继续大笑着回答:“嗨,嗨。”餐馆里的每个人都看着我们,脸色古怪

    ③我们点的饭菜来了,那个老头大喊:“你们点小馅饼蛋糕了吗?你们知道躲猫猫(一种把脸一隐一现以逗小孩的游戏)吗?嗨,瞧,他知道躲猫猫。”没有人认为那老头是可爱的,他显然喝醉了,我和我丈夫感到很困窘。我们默默地吃着饭,伊瑞克则在为那个欣赏他的流浪汉表演自己的拿手好戏,那个老头把他大大地赞美了一番。

    ④我们终于吃完了饭,丈夫去结账,我抱着伊瑞克去停车场等他。那老头就稳稳地坐在门口。“上帝,让我在他对伊瑞克说话之前顺利地走出去吧。”我在心里祈祷着。当我走近那个老头的时候,我转过身,试图横跨一步躲过他,避免他呼出的空气吹到我们脸上。但是,当我这么做的时候,伊瑞克努力把小小的身体向外斜伸出去,张着胳膊,做出“抱抱我”的姿势。我还没来得及阻止他,伊瑞克就已经从我的怀里向那个老头扑过去了。

    ⑤一刹那间,一个身上带着臭味的老人和一个充满乳味的小婴儿的爱达到了完美的极致。伊瑞克表现出来的是完全的信任和爱,他温顺地把他的小脑袋靠在老人肩膀上。老人的眼睛紧闭着,我看见泪珠在他的睫毛上闪烁着。他用他充满污垢、痛苦和艰辛劳作的手托着婴儿,抚摸着他的后背。这么短的时间里他们建立起这么深厚的爱,我站在旁边,肃然起敬。老头抱着伊瑞克,轻轻地摇着,用一种坚定的、命令的口吻对我说:“你要好好照顾这个孩子。”我的喉咙里像卡着一块石头,好不容易才说:“我会的。”他颇不情愿地将伊瑞克递给我,看起来非常伤心。我接过伊瑞克,那老头又说:“愿上帝保佑你,太太,你已经给了我一份最珍贵的礼物。”

    ⑥我除了低声说“谢谢”之外什么也说不出来。我抱着伊瑞克,向汽车跑去。丈夫看到我哭,并且把伊瑞克抱得那么紧时,他感到莫名其妙,只有我知道为什么。我刚刚亲眼目睹了一个看不见罪恶、不懂得评判的小婴儿表现出来的爱。我的伊瑞克看见的是一个人的内心,而我,他的妈妈,看到的则是一套衣服。这是我的小婴儿给我上的最好的一课。

(选自《幽默与讽刺》2011年第2期)

同类题4

根据短文内容,判断正误。

     "How are you?" is a nice question. It's a friendly way that people in the USA greet each other. But "How are you?" is also a very unusual question. It's a question that often doesn't need an answer. The person who asks "How are you?" hopes to hear the answer "Fine", even if the person's friend isn't fine. The reason is that "How are you?" isn't really a question and "Fine"

isn't really an answer. They are simply other ways of saying "Hello" or "Hi".

     Sometimes, people also don't say exactly what they mean. For example, when someone asks "Do you agree?", the other person might think, "No, I disagree. I think you're wrong..." But it isn't very polite to disagree so strongly, so the other person might say "I'm not sure." It's a nicer way to say that you don't agree with someone.

     People also don't say exactly what they are thinking when they finish talking with other people. For example, many talks over the phone finish when one person says "I have to go now." Often, the person who wants to hang up gives an excuse: "Someone is at the door." "Something is burning on the stove." The excuses might be real, or not. Perhaps the person who wants to hang up simply doesn't want to talk any more, but it isn't polite to say that. The excuse is more polite, and it doesn't hurt the other person.

     Whether they are greeting each other, talking about an idea, or finishing a talk, people don't say exactly what they are thinking. It's an important way that people try to be nice to each other, and it's part of the game of language.

根据短文内容,判断正(T)误(F)。