题干

地球的极半径是6357千米,赤道半径是6378千米,平均半径是6371千米。因此严格地说,地球的形状是一个(  )

A:正球体

B:圆

C:圆柱体

D:赤道略鼓、两极稍扁的不规则球体

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D

同类题3

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    The fence was long and high. He put the brush into the whitewash and moved it along the top of the fence. He repeated the operation. He felt he could not continue and sat down.

    He knew that his friends would arrive soon with all kinds of interesting plans for the day.

    They would walk past him and laugh. They would make jokes about his having to work on a beautiful summer Saturday. The thought burned him like fire.

    He put his hand into his pockets and took out all that he owned. Perhaps he could find some way to pay someone to do the whitewashing for him. But there was nothing of value in his pockets—nothing that could buy even half an hour of freedom. So he put the bits of toys back into his pockets and gave up the idea.

    At this dark and hopeless moment, a wonderful idea came to him. It filled his mind with a great, bright light. Calmly he picked up the brush and started again to whitewash.

    While Tom was working, Ben Rogers appeared. Ben was eating an apple as he walked along the street. As he walked along it, he was making noises like the sound of a riverboat. First he shouted loudly, like a boat captain. Then he said “Ding-Dong-Dong”,“Ding-Dong-Dong” again and again, like the bell of a riverboat. And he made other strange noises. When he came close to Tom, he stopped.

    Tom went on whitewashing. He did not look at Ben. Ben stared a moment and then said: “Hello! I'm going swimming, but you can't go, can you?”

    No answer. Tom moved his brush carefully along the fence and looked at the result with the eye of an artist. Ben came nearer. Tom's mouth watered for the apple, but he kept on working.

    Ben said, “Hello, old fellow, you've got to work, hey?”

    Tom turned suddenly and said, “Why, it's you, Ben! I wasn't noticing.”

     “Say—I'm going swimming. Don't you wish you could? But of course you'd rather work—wouldn't you? Of course you would.”

    Tom looked at the boy a bit, and said, “What do you call work?”

     “Why, isn't that work?”

    Tom went back to his whitewashing, and answered carelessly.

     “Well, maybe it is, and maybe it isn't. All I know is, it suits Tom Sawyer.”

     “Oh come, now, you don't mean to say that you like it?”

    The brush continued to move.

     “Like it? Well, I don't see why I shouldn't like it. Does a boy get a chance to whitewash a fence every day?”

    Ben stopped eating his apple. Tom moved his brush back and forth, stepped back to look at the result, added a touch here and there, and stepped back again. Ben watched every move and got more and more interested. Soon he said,“Say, Tom, let me whitewash a little.”

    Tom thought for a moment, and was about to agree, but he changed his mind.

     “No—no—it won't do, Ben. You see, Aunt Polly wants this fence to be perfect. It has got to be done very carefully. I don't think there is one boy in a thousand, maybe two thousand, that can do it well enough.”

     “No—is that so? Oh come, now—let me just try. Only just a little.”

“Ben, I'd like to, but if it isn't done right, I'm afraid Aunt Polly ”

     “Oh, I'll be careful. Now let me try. Say—I'll give you the core of my apple.”

     “Well, here—No, Ben, now don't. I'm afraid …”

     “I'll give you all of it.”

    Tom gave up the brush with unwillingness on his face, but joy in his heart. And while Ben worked at the fence in the hot sun, Tom sat under a tree, eating the apple, and planning how to get more help. There were enough boys. Each one came to laugh, but remained to whitewash. By the time Ben was tired, Tom sold the next chance to Billy for a kite; and when Billy was tired, Johnny bought it for a dead rat—and so on, hour after hour. And when the middle of the afternoon came, Tom had won many treasures.

    And he had not worked. He had had a nice idle time all the time, with plenty of company, and the fence had been whitewashed three times. If he hadn't run out of whitewash, Tom would have owned everything belonging to his friends.

    He had discovered a great law of human action, namely, that in order to make a man or a boy want a thing, it is only necessary to make the thing difficult to get.

同类题5

阅读下文,回答相关问题。

                                                                                                   爱的礼物
         ①三天假期,飞快过去了。
         ②下午又要回到乡村的单位去。
         ③妈妈系着围裙,在灶房里给我赶做饼子,是那卷了葱花、调料和鸡蛋的馅饼。她一边做,一边不停的叮咛我回去好好工作好好工作。三天来,她一直都在这么说,我有点烦,想表示一点不满,但望一眼她挂着汗珠的脸庞,心又一下子软了。妈妈总让我心软,总是用爱把我驯服得乖乖的,我听着她永远叮嘱不完的话语,态度顺从得像一个很听话的孩子。
        ④当妈妈的叮咛终于出现一段间隙的沉默,我赶紧趁机逃出了灶房。
        ⑤外面飘着细雨,我站在院子里享受一份湿意,风和雨星子一起吹过来,好沁香的丁香味儿钻入鼻孔,我这才回头注视花园里的丁香树。这是一颗妈妈亲手栽培出来的白丁香,细细碎碎的枝头上,挂满了一串串洁白的丁香花,沐浴在雨露中,更显了几分娇白,湿嫩嫩的,很是美丽。我不禁脱口道:“这么美丽的丁香花,我真想折两枝带到乡下去!”喊完竟呆呆站在了丁香树前痴情了好大半天。
        ⑥雨大起来了。我深深的凝视了一会儿带着水珠的花姿,然后很是不舍地躲回自己的小屋收拾东西。
        ⑦一只大大的天蓝色旅行包,首先装进去的,总是进城一次逛书店买回的新书和稿纸,这是唯一我自己置办的东西。而其他塞满包的,便是妈妈永远赠送不完的爱的礼物。妈妈经常变魔术似的,将肉、面粉、菜做成各式各样的食品,笑眯眯的送给我,就连怎样吃,一次吃多少以及如何存放等等,她都要一遍又一遍的提醒到我出门才肯罢休,她知道我怕冷,总是要我多加衣服多加衣服;我喜淋雨,可她非要把雨伞塞进我的包里,而我不经意的一声咳嗽,她便凶着脸将那吓人的药片放在我手中。她很是细微,就连我平时馋嘴的果丹皮、泡泡糖、锅巴之类,她都会细心替我装好。反正,每次离家,非得背一个满满的包,她才肯放我走。
        ⑧我常想,母亲干嘛有那么多的爱呢?从小至今,我已背负了许许多多,可她依然源源不断地爱我,给我无穷无尽的爱的礼物,而她实在就是那么一个瘦瘦弱弱的样子,她那丰厚肥腴的爱,究竟在什么地方蕴藏呢?凝望她,我总也想不透。
        ⑨东西收拾得差不多了,那包也越来越鼓,抬头向窗外望去,雨依旧。突然发现妈妈踩着小凳子站在丁香树前。我倚窗仔细望去她正拿着剪刀一下又一下的采摘这丁香花。她面带微笑,用指尖拨弄着丁香枝条,细心又专注的挑选着一串串丁香花,她的表情和她的一伸手、一曲臂、一挥剪刀又一弯腰的姿势,在这一刻显得极为优美、和谐、摄人心魄。一时间,我竟被她的美丽惊呆了,我从没注意过妈妈也会有这般美丽的时刻。我本想跑出去给她雨伞的,但我怕破坏了这一刻的美妙,怕弄惨这幅雨季生动的风景。是的,这的确是一幅极真极美的风景:一个劳累一生的母亲,为出门工作的女儿,冒雨采摘爱的鲜花,多皱的脸上满是汗水和雨水,但她微笑得宽慰而灿烂,笑得一尘不染,就像那一尘不染的丁香花一样,又美又芬芳。
        ⑩我呆呆的注视着妈妈许久许久,热泪潮涌般滚下来,滑进嘴里,甜甜的、又涩涩的,很是叫人心绞。当妈妈终于捧着一大把含露的白丁香送到我手中时,我那颗脆弱的、承受不了太多爱与美的心,已有种清脆崩塌的感觉。
        ⑪我背起包,极为珍爱的捧着鲜花出门,妈妈一直笑笑地、笑笑地送我到巷口。花在我怀中美丽的芳香着,转头看妈妈,她依然笑笑地,笑得跟丁香一样芬芳,跟丁香一样的纯洁,跟丁香一样一样的馨香、俊美……