阅读理解 The Ostrich
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 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.

单选题 1.The ostrich is known to us as the largest bird in the human history.

单选题 2.With the help of its long legs and extended wings, ostrich can run very fast.

单选题 3.The female ostrich often lay all its eggs in the neighboring nests.

【正确答案】 B

【答案解析】题干要求判断母鸵鸟是否常常把自己所有的卵产在临近的巢里。文中第二段讲到了鸵鸟产卵的情况，母鸵鸟每个雨季会产大概二十枚卵，但是并非都在自己的巢穴里，“she goes off in search of the nests of neighboring females and lays two or three eggs in each of them”，到最后才把“eight or nine eggs”产在自己的巢穴里。所以题干表述是错误的。

单选题 4.The male ostrich would help its mate to hatch their eggs.

单选题 5.The size of the eggs is so large that the female ostrich can only lay at most one egg every two days.

单选题 6.When the female ostrich lays eggs in its own nest, she will never leave there in order to protect her eggs.

单选题 7.The ostrich can only cover about twenty eggs at the same time.

单选题 8.The female ostrich can't distinguish her own eggs from others so that she often pushes some of her own eggs out of the nest.

【正确答案】 B

【答案解析】题干要求判断母鸵鸟是否不能区分自己产的卵和别的鸵鸟产的卵，所以常常把自己的卵推出巢穴。第四段最后一句话讲到“it is not difficult for her to distinguish her own from those of strangers”，即“区分是否是自己产的卵对母鸵鸟来说并不难”，所以“The rejected eggs，however，never include any of her own”，即“推出去的卵都不会是自己产的”，所以题干表述是错误的。

单选题 9.At night, the male ostrich don't protect their nests because they should go out for food.

【正确答案】 C

【答案解析】题干要求判断夜里公鸵鸟是否因为外出觅食而不保护他们的巢穴。最后一段里提到了在孵化小鸵鸟期间，“there are too few males to sit on all the nests at night”，所以有些天敌“raid the nests and eat the eggs”，但是并没有提到公鸵鸟不在是因为要外出觅食，因此无法判断题干是否正确。