首页
登录
职称英语
[originaltext] Many egglaying animals merely lay their eggs and leave. With
[originaltext] Many egglaying animals merely lay their eggs and leave. With
游客
2023-07-12
47
管理
问题
Many egglaying animals merely lay their eggs and leave. With turtles for instance, the eggs hatch on their own. The current theory about birds is that the earliest birds did just that, when they were coldblooded creatures living in warm places. However when they became warmblooded creatures living in cold places they had to remain on top of the eggs to keep them warm. This process we call incubation. For this they needed a place, a nest very likely the first nests were just primitive depressions scraped into the ground. Even now many species still lay eggs in this sort of crude nest. In fact, every spring a mother killdeer lays her eggs in scene pebbles along the edged the parking lot just outside this building. Primitive nests on the ground were fine for some birds but others began to elevate their nests onto Branches, perhaps to avoid predators. These early elevated nests were probably loose platforms of sticks and twigs, the types still built by ospreys and mostarians today. The latest evolutionary development in nests the most re cent version, so to speak, is the cupshaped nest. This is the one we regard today as the typical bird’s nest, you know, like a robin’s nest.
选项
A、They began to lay eggs.
B、They changed their migration patterns.
C、Their flying ability improved greatly.
D、They become warmblooded.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/2830015.html
相关试题推荐
[originaltext]TheLondon’sDistrictCourtdismissedthedamagesuitbrought
[originaltext]TheLondon’sDistrictCourtdismissedthedamagesuitbrought
[originaltext]TheLondon’sDistrictCourtdismissedthedamagesuitbrought
[originaltext]WhenIfirstwenttoLondonasastudent,Isataloneduring
[originaltext]Thedaystartedbadly,IwokeuplatebecauseIforgotabout
[originaltext]M:Hello,LiLi.Comeonin.How’veyoubeenkeepingrecently?W:
[originaltext]M:Hello,LiLi.Comeonin.How’veyoubeenkeepingrecently?W:
[originaltext]M:Hello,LiLi.Comeonin.How’veyoubeenkeepingrecently?W:
[originaltext]M:Areyoubusytonight?Iwanttoaskyoutogotothemovies.W
[originaltext]M:Areyoubusytonight?Iwanttoaskyoutogotothemovies.W
随机试题
Intheinformationtechnologyindustry,itiswidelyacknowledgedthathoww
When______whytheyarelookingforjobsatnewcompanies,someofthemsaythey
[originaltext]GeneralizingabouteducationintheUnitedStatesinvolvesso
Peoplebecomequiteillogicalwhentheytrytodecidewhatcanbeeatenand
共用题干 马先生2008年1月采用组合贷款法购买了住房一套,购买当月开始还款。
公布运价自国务院交通主管部门受理备案之日起满()生效。A.15日 B.3
季节性资产增加的主要融资渠道有()A:季节性负债增加:应付账款和应计费用B:内
根据《关于学习贯彻〈规划环境影响评价条例〉加强规划环境影响评价工作的通知》,严格
A.骨瘤 B.内生软骨瘤 C.转移癌 D.骨巨细胞瘤 E.骨软骨瘤好发于
对项目经理项目成本岗位责任责任考核的检查方法是()。A.查看有无组织结构图 B
最新回复
(
0
)