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Text 3The ostrich the largest bird in the wor

2022-08-05 18:19:23 问答库 阅读 170 次

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Text 3
The ostrich, the largest bird in the world at present, lives in the drier regions of Africa outside the actual deserts. Because of its very long, powerful legs and the floating effect of its extended wings, it is able to run at great speed over considerable distances.
The female ostrich normally produces about twenty eggs every rainy season. When the female ostrich begins to lay her eggs, however, she does not begin in her own nest. Instead she goes off in search of the nests of neighboring females and lays two or three eggs in each of them. By the time she has laid eight or nine eggs, she returns and lays the rest in her own nest.
Because of the size of the eggs, the female ostrich cannot lay more than one every two days, so it takes her three weeks to finish laying in her own nest. During that period, she spends a lot of time away from her nest looking for food. And while she is off her nest, other females visit it to lay their eggs amongst hers. By the time she is ready to sit on the eggs to hatch them, there could be up to thirty eggs in her nest, over half of which are not her own.
The female ostrich can comfortably cover only about twenty eggs when she is sitting on the nest, so before settling down she pushes the surplus ten or so eggs out of the nest. The rejected eggs , however, never include any of her own. Each female is remarkably consistent in the size and shape of the eggs she produces, so it is not difficult for her to distinguish her own from those of strangers.
Of all the eggs laid by a colony of ostriches, only a very small number hatch into young birds. There are times when nests are left unprotected, for there are too few males to sit on all the nests at night. Thus there are ample opportunities for their natural enemies to raid the nests and eat the eggs. In fact, nearly 80% of the nests are destroyed. But even if a particular female"s nest suffers this fate, there is a good chance that one or two of her eggs will be hatched in the nest of one of
her neighbors.
56. We learn from the text that an ostrich can go a long distance at high speed as_________
[A] it is a special kind of bird
[B] it lives in large desert areas
[C] it has special wings and legs
[D] it is the largest bird in the world请帮忙给出正确答案和分析,谢谢!

参考答案

正确答案:C
参考译文鸵鸟是目前世界上最大的鸟类,生活在非洲真正的沙漠外围比较干燥的地域。因为它们的腿又长又有劲,伸展开翅膀有一定的浮力,鸵鸟可以快速地奔跑很长的距离。每到雨季,一只雌鸵鸟通常可以产大概二十个蛋。但是,当雌鸵鸟开始产蛋时,它一开始并不是产在自己的巢中。相反,它四处寻找附近雌鸵鸟的巢穴,然后在它们的巢中分别产下两至三个蛋。当产下大约八九个蛋的时候,它返回到自己的巢中产下其余的蛋。由于鸵鸟蛋很大,雌鸵鸟每两天最多能产一个蛋,所以它要花三个星期在自己的巢中产蛋。在这期间,雌鸵鸟很多时候必须离开家去觅食物吃。当它外出找食物时,别的雌鸵鸟来了,也把它们自己的蛋产在它的窝中。鸵鸟准备孵蛋时,它的窝中已多达三十个蛋,其中有一半以上不是它自己的。当雌鸵鸟孵蛋的时候,它只能很舒适地盖住大约二十个鸵鸟蛋;因此在孵蛋之前,雌鸵鸟会把多余的十多个鸵鸟蛋挤出窝。但是,那些被挤出去的鸵鸟蛋里从来不会有它自己的蛋。每只鸵鸟的蛋的大小和形状非常一致,从而很容易就可以区分自己的蛋和其他鸵鸟的蛋。在一群鸵鸟产下的蛋中,只有很小一部分会被孵化成小鸟。雌鸵鸟的鸟巢有时缺少足够的保护,因为雄鸵鸟实在太少了,在晚上无法保护所有的鸟巢。所以鸵鸟的天敌总是有很多机会偷袭鸟巢并吃掉鸵鸟蛋。事实上,几乎80%的巢穴会被摧毁掉。但是,即使某一只鸵鸟的巢穴会遭受这样的命运,在附近的鸵鸟的巢穴中它的一两个蛋仍会有很大的机会被孵化成功。56.C【精析】细节题。题干意为“从文章我们可知鸵鸟可以以很快的速度跑很远是因为____。”从文章的第一段我们知道,是因为鸵鸟特殊的翅膀和腿。故选C。

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