首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The ostrich, the largest bird in the world at present, lives in the drier regions of Africa outside the actual deserts. Because
The ostrich, the largest bird in the world at present, lives in the drier regions of Africa outside the actual deserts. Because
admin
2010-01-09
100
问题
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.
The female ostrich identifies her own eggs by their size and ______.
选项
A、color
B、number
C、shape
D、weight
答案
C
解析
细节题。根据第四段第三句知对于每只雌鸵鸟来说,他们产的蛋有固定的大小和形状,故分辨自己所产的蛋对于他们来说并不难。所以答案为C。
转载请注明原文地址:https://kaotiyun.com/show/Ls3d777K
本试题收录于:
公共英语三级笔试题库公共英语(PETS)分类
0
公共英语三级笔试
公共英语(PETS)
相关试题推荐
Generallyspeaking,aBritishiswidelyregardedasaquiet,shyandconservativepersonwhois【21】onlyamongthosewithwhomhe
Nowadays,airtravelisvery【21】.WearenotsurprisedwhenwewatchonTVthatapoliticianhastalkedwithFrenchPresidentin
Aspartofmorecomprehensivecomplianceandethicsprograms,manycompanieshaveformulatedinternalpoliciespertainingtothe
Aspartofmorecomprehensivecomplianceandethicsprograms,manycompanieshaveformulatedinternalpoliciespertainingtothe
Recentresearchhadclaimedthatanexcessofpositiveions(离子)intheaircanhaveanill-effectonpeople’sphysicalorpsych
TheWorldHealthOrganization(WHO)isintrouble.Itsleaderisaccusedoffailingtolead,andastheorganizationdrifts,oth
ManyUnitedStatescompanieshave,unfortunately,madethesearchforlegalprotectionfromimportcompetitionintoamajorline
Nobodycanbereallyfreefromthesound.Whetherweliveinthemiddleofamoderncityorafarawayvillage,wearesurrounded
Inlessthan30year’stimetheStarTrekholodeckwillbeareality.Directlinksbetweenthebrain’snervoussystemandacomp
随机试题
Peopleusedtothinkthatlearningtwolanguagescreatedconfusioninthemind.Far【C1】________itwasthought,togetoneright
芜菁原产于中国,我国自古即有种植。()
肺炎时可减轻胸痛的最常用体位是()
患者,男性,50岁,2型糖尿病10年,近半个月来发现双下肢水肿,并逐渐加重,常感乏力,头晕,遂来医院就诊,查血清白蛋白25g/L,血清胆固醇及甘油三醇升高,血肌酐、尿素氨正常,查体:血压170/110mmHg,双下肢重度可凹性水肿。责任护士对患者出院前
不适宜在CT引导下腹腔穿刺的脏器是
关于糖尿病的胰岛素治疗,正确的是
处理患者投诉需要注意的是
与普通股筹资方式相比,优先股筹资方式的优点是()。(2012年)
研究表明,整个测验测试难度指数分布在0.30至0.70之间,而整个测验的难度指数最好在()时,这样不仅使测验对被试有较大的鉴别力,而且可以使测验分数接近正态分布。
根据物权法规定,土地承包经营权的设立时间是()。(2012年单选27)
最新回复
(
0
)