绝妙的艺术珍品——鸟卵 我们都见过鸡蛋和鸭蛋。鸡蛋的色泽有黄红色的,也有白色的

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问题:

绝妙的艺术珍品——鸟卵

  我们都见过鸡蛋和鸭蛋。鸡蛋的色泽有黄红色的,也有白色的,而鸭蛋却是青白色的,它们是最普通的鸟卵。世界上近九千种鸟类,它们的卵大小不一,颜色各异,形状不同,千变万化。绿的形如翡翠,蓝的恰似宝石,白的好象玉石,红的如同玛瑙。卵壳表面的斑驳点块,就跟镶嵌在上面的五颜六色的珍珠一样,闪闪发光,耀眼夺目。它是大自然赐给人类的绝妙的艺术珍品。

  鸿雁的卵壳黄中透红;白鹭的卵壳为翠绿色,短翅树莺的卵壳是红宝石色,喜鹊和乌鸦的卵壳呈美丽的天蓝色;鹌鹑的卵壳呈褐色且带有深褐斑块;夜鹰的卵壳上有如大理石般的云……,形形色色,不胜枚举。就形状而言,除最普通的椭圆形外,还有锥形、钝椭圆形、球形等等。世界上最大的鸟卵,莫过于前不久已经灭绝了的象乌卵。象鸟是类似鸵鸟的一种大型鸟类,它的卵是普通鸡蛋的148倍,大致相当6个鸵鸟卵那么大,而一个鸵鸟卵重,大约是1.5公斤,那么也就是说,一个象鸟重9公斤,难怪那时非洲的土著居民用象鸟卵贮藏甜酒,这个容器可藏9升多呢!世界上最小的卵,要算产在南美洲的蜂鸟了,它的卵重仅0.5克,相当于一颗绿豆大小,30000个蜂鸟卵才相当于一个象鸟卵。同是鸟,卵而相差如此之悬殊,实在令人惊叹!

  卵壳上为什么有这样许多不同的花纹和斑块呢?原来它们在巧妙地运用保护色来迷惑敌人,可免遭被吞食的厄运。

你见过有花纹的鸟卵吗?它们的花纹色泽与周围的环境总是很接近,这又是为什么呢?

考点:鸟的生殖和发育
题型:问答题

( )对托管业务准入有详细的规定,如最近3个会计年度的年末净资产均不低于20亿元人民币。

A.《证券投资基金法》

B.《证券投资基金托管资格管理办法》

C.《证券法》

D.《证券投资基金运作管理办法》

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天津某外贸公司从韩国进口“现代”牌汽车一辆,成交价格为CIF天津USD25000,进口关税税率为100%,外汇基准价USD100=RMB871,消费税率为8%,应征消费税是()元(消费税额计算到元)。

A.217 750

B.435 500

C.37 870

D.17 420

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Urbanization

(2013·高考北京卷)Until relatively recently,the vast majority of human beings lived and died without ever seeing a city.The first city was probably founded no more than 5,500 years ago.__ 小题1:__In fact,nearly everyone lived on farms or in tiny rural (乡村的) villages.It was not until the 20th century that Great Britain became the first urban society in history—a society in which the majority of people live in cities and do not farm for a living.

Britain was only the beginning. 小题2:__The process of urbanization—the migration (迁徙) of people from the countryside to the city—was the result of modernization,which has rapidly transformed how people live and where they live.

In 1990,fewer than 40% of Americans lived in urban areas.Today,over 82% of Americans live in cities.Only about 2% live on farms.__ 小题3:__

Large cities were impossible until agriculture became industrialized.Even in advanced agricultural societies,it took about ninety­five people on farms to feed five people in cities._ 小题4:_Until modern times,those living in cities were mainly the ruling elite(精英) and the servants,laborers and professionals who served them.Cities survived by taxing farmers and were limited in size by the amount of surplus food that the rural population produced and by the ability to move this surplus from farm to city.

Over the past two centuries,the Industrial Revolution has broken this balance between the city and the country. 小题5:_Today,instead of needing ninety­five farmers to feed five city people,one American farmer is able to feed more than a hundred non­farmers.

A.That kept cities very small.

B.The rest live in small towns.

C.The effects of urban living on people should be considered.

D.Soon many other industrial nations became urban societies.E.But even 200 years ago,only a few people could live in cities.

F.Modernization drew people to the cities and made farmers more productive.

G.Modern cities have destroyed social relations and the health of human beings.

题型:问答题

根据右图提供的信息,下列所得结论不正确的是(     )

A.反应物比生成物稳定

B.该图可以表示石灰石高温分解

C.该反应的△H>0

D.因为生成物的总能量高于反应物的总能量该反应一定需要加热

题型:问答题

定义应用需求的原型生命周期应是一个迭代过程,而其迭代工作量主要集中在 【11】 

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