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
Birds are warm-blooded, vertebrate animals whose bodies are covered with feathers. Other characteristics of birds are: wings; a
Birds are warm-blooded, vertebrate animals whose bodies are covered with feathers. Other characteristics of birds are: wings; a
admin
2012-09-17
76
问题
Birds are warm-blooded, vertebrate animals whose bodies are covered with feathers. Other characteristics of birds are: wings; a short tail bone; the visible tail being composed entirely of feathers; a weak or nonexistent sense of smell; no teeth; and keen hearing, despite the absence of external ears. As in mammals (哺乳动物), the only other group of warm-blooded animals, the blood in the veins (静脉) of birds is kept totally separated from the blood in the arteries (动脉).
Birds evolved from reptiles, especially from some small dinosaur-relative. Gradually the scales of the dinosaur evolved into feathers, perhaps first for insulation as the animal evolved from cord to wing blade but later for flight. It is still unknown, however, whether flight developed when a ground-living form began to flap its wings to increase its running speed (like the ostrich today), or when a tree climbing form used imperfect wings to aid it in leaping from tree limb to tree limb. The evolution from reptile to the bird as we know it concluded about 75 million years ago, at the beginning of the Tertiary period, or age of mammals.
The earliest classification of birds relied upon easily recognized external characteristics or upon peculiarities of behavior or appearance. For example, all web-footed birds were grouped together and all seed-eating birds were grouped together. Since the 19th century and the general acceptance of evolution, however, this method has given way to a sounder and more scientific procedure. Birds, as well as all other living things, are now classified in a way that best expresses their blood relationships and lines of descent. This kind of classification is known as a phylogenetic classification (系谱分类).
选项
A、piece of science fiction (科幻小说)
B、lecture
C、romantic story
D、news story
答案
B
解析
本题考察对文章文体的把握。这是一篇关于鸟类的文章,作者用客观、科学的语言向我们讲述了鸟类的特征、进化和分类。文中大量专业术语表明它节选自学术类讲座,因此选B。
转载请注明原文地址:https://kaotiyun.com/show/DSlK777K
本试题收录于:
大学英语三级A级题库大学英语三级分类
0
大学英语三级A级
大学英语三级
相关试题推荐
A—socialisteconomyB—capitalisteconomyC—collectiveeconomyD—plannedeconomyE—c
AnewreportoftheUnitedNationsshowsthat,ifthepresentgrowthrateof2percentperyearcontinues,today’sworldpopulat
Atthebeginningofthepassage,"MountainGorilla"and"ShortTailedChinchilla"seemtobesome______.Asthereportpredict
Wehavelittlechancetodiscussproblemwiththeteachersconcernedortodomorethanglanceatthebooksbeingused.
People______(live)comfortablyinthetownshardlyfeelthepleasureoflivinginthecountry.
Peterworkedsofastwiththemathsproblems______alotofmistakes.
Whatcanyourfriendsdowhentheyhavetime?Theycan______and______whentheyhavetime.
Withthedevelopmentoftheeconomy,advertisementshavebecomeincreasinglyimportantindailylife.Advertisementscangiv
Withthedevelopmentoftheeconomy,advertisementshavebecomeincreasinglyimportantindailylife.Advertisementscangiv
Halloweenoriginatedasacelebrationconnectedwithevilspirits.Witchesflyingonbroomstickswithblackcats,ghosts,gobli
随机试题
男婴,5天,足月顺产,生后2天出现拒奶,反应差,体温38℃,黄疸。其母亲病史中最具诊断价值的是
男性患者,43岁,从2m处掉下2天,出现肝区剧痛1小时,伴寒战、高热,查:巩膜轻度黄染,肝区及右上腹有明显的压痛,腹肌紧张,右膈肌升高,运动受限,血压80/55mmHg,脉搏98次/分。
龋病资料整理一般不以哪项分组
3个月婴儿牛乳喂养正确的是
A.膀胱根治切除术B.姑息性放疗C.经尿道膀胱肿瘤电切术D.膀胱部分切除术E.经尿道膀胱肿瘤电切+膀胱灌注化疗T3期膀胱尿路上皮癌,首选的治疗方法是
两样本率比数的四格表X2检验,4个格子的基本数据是
合同转让是指合同的( )发生了变化。
注册建造师施工管理签章文件的签章主体是()的注册建造师。
下列关于我国古代监察体制的说法,正确的是:
JackalsosaidthathewouldbebackonDecember25th.Jackalsosaidthathewouldnotbeback________December25th.
最新回复
(
0
)