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
自考
Rare Fossil Record The preservation of embryos and juveniles is a rare occurrence in the fossil record. The tiny, delicate s
Rare Fossil Record The preservation of embryos and juveniles is a rare occurrence in the fossil record. The tiny, delicate s
admin
2022-01-21
71
问题
Rare Fossil Record
The preservation of embryos and juveniles is a rare occurrence in the fossil record. The tiny, delicate skeletons are usually scattered by scavengers(食腐动物) weathering before they can be fossilized. Ichthyosaurs(鱼龙) had a higher chance of being preserved than did terrestrial creatures because, as marine animals, they tended to live in environments less subject to erosion. Still, their fossilization required a suite of factors; a slow rate of decay of soft tissues, little scavenging by other animals, a lack of swift currents and waves to jumble and carry away small bones, and fairly rapid burial. Given these factors, some areas have become a treasury of well-preserved ichthyosaur fossils.
The deposits at Holzmaden, Germany, present an interesting case for analysis. The ichthyosaur remains are found in black, bituminous marine shales(页岩) deposited about 190 million years ago. Over the years, thousands of specimens of marine reptiles, fish and invertebrates have been recovered from these rocks. The quality of preservation is outstanding, but what is even more impressive is the number of ichthyosaur fossils containing preserved embryos.
Ichthyosaurs with embryos have been reported from 6 different levels of the shale in a small area around Holzmaden, suggesting that a specific site was used by large numbers of ichthyosaurs repeatedly over time. The embryos are quite advanced in their physical development; their paddles, for example, are already well formed. One specimen is even preserved in the birth canal. In addition, the shale contains the remains of many newborns that are between 20 and 30 inches long.
Why are there so many pregnant females and young at Holzmaden when they are so rare elsewhere? The quality of preservation is almost unmatched and quarry operations have been carried out carefully with an awareness of the value of the fossils. But these factors do not account for the interesting question of how there came to be such a concentration of pregnant ichthyosaurs in a particular place very close to their time of giving birth.
Which of the following best expresses the relationship between the first and second paragraphs?
选项
A、The first paragraph describes a place while the second paragraph describes a field of study.
B、The first paragraph defines the terms that are used in the second paragraph.
C、The second paragraph describes a specific instance of the general topic discussed in the first paragraph.
D、The second paragraph presents information that contrasts with the information given in the first paragraph.
答案
C
解析
推理判断题。第二段是第一段讲述内容的一个例证,因此C正确。
转载请注明原文地址:https://kaotiyun.com/show/z08R777K
本试题收录于:
英语(二)题库公共课分类
0
英语(二)
公共课
相关试题推荐
Allbirths,marriagesanddeathsareenteredintheofficial______(record).
Somepeoplearetooparticularaboutschoolrecords,insistingthateveryapplicant______alldiplomasfromelementaryschoolto
RareFossilRecordThepreservationofembryosandjuvenilesisarareoccurrenceinthefossilrecord.Thetiny,delicates
RareFossilRecordThepreservationofembryosandjuvenilesisarareoccurrenceinthefossilrecord.Thetiny,delicates
KareFossilRecordThepreservationofembryosandjuvenilesisarareoccurrenceinthefossilrecord.Thetiny,delicatesk
KareFossilRecordThepreservationofembryosandjuvenilesisarareoccurrenceinthefossilrecord.Thetiny,delicatesk
RareFossilRecordThepreservationofembryosandjuvenilesisarareoccurrenceinthefossilrecord.Thetiny,delicates
随机试题
复合树脂最大的优点()
持续经营假设是假设企业可以一直经营下去,即使进入破产清算,也不应该改变会计核算方法。()
关于国库单一账户体系中各类账户的功能,下列说法正确的有()。
预测央行可能降息,在基金合同允许范围内,为提高债券基金的收益率,基金经理可能进行的操作有()。Ⅰ.提高杠杆率Ⅱ.降低杠杆率Ⅲ.提高组合久期Ⅳ.降低组合久期
应计入存货采购成本的有()。
注册会计师在执行对甲公司2011年度财务报表的审计时,关于注册会计师的审计总体目标,表述恰当的有()。
IPO是指一家企业或公司(股份有限公司)第一次将它的股份向公众出售。根据《中华人民共和国证券法》(以下简称《证券法》)中对其发行要求,以下不正确的是()。
根据操作对象的不同可将操作技能分为()。
《中华人民共和国物权法》第二十条规定:当事人签订买卖房屋或者其他不动产物权的协议,为保障将来实现物权,按照约定可能向登记机构申清预告登记。预告登记后,未经预告登记的权利人同意,处分该不动产的,不发生物权效力。预告登记后,债权消灭或者自能够进行不动
Asoneworkswithcolorinapracticalorexperimentalway,oneisimpressedbytwoapparentlyunrelatedfacts.Colorasseenis
最新回复
(
0
)