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
Fossils are the remains and traces of ancient plant and animal lives that are more than 10,000 years old. They range in size fro
Fossils are the remains and traces of ancient plant and animal lives that are more than 10,000 years old. They range in size fro
admin
2010-07-06
61
问题
Fossils are the remains and traces of ancient plant and animal lives that are more than 10,000 years old. They range in size from microscopic structures to dinosaur skeletons and complete bodies of enormous animals. Skeletons of extinct species of human are also considered fossils.
An environment favorable to the growth and later preservation of organisms is required for the occurrence of fossils. Two conditions are almost always present: The possession of hard parts, either internal or external, such as bones, teeth, scales, shells, and wood; these parts remain after the rest of the organism has decayed. Organisms that lack hard parts, such as worms and jelly fish have left a meager geologic record. Quick burial of the dead organism, so that protection is afforded against weathering, bacterial action, and scavengers.
Nature provides many situations in which the remains of animals and plants are protected against destruction. Of these, marine sediment is by far the most important environment for the preservation of fossils, owing to the incredible richness of marine life. The beds of former lakes are also prolific sources of fossils. The rapidly accumulating sediments in the channels, floodplains, and deltas of streams bury fresh-water organisms, along with land plants and animals that fall into the water. The beautifully preserved fossil fish from the Green River soil shale of Wyoming in the western Unit- ed States lived in a vast shallow lake.
The frigid ground in the far north acts as a remarkable preservative for animal fossils. The woolly mammoth, a long-haired rhinoceros and other mammals have been periodically exposed in the tundra of Siberia, the hair and red flesh still frozen in cold storage.
Volcanoes often provide environments favorable to fossil preservation. Extensive falls of volcanic ash and coarser particles overwhelm and bury all forms of life, from flying insects to great trees. Caves have preserved the bones of many animals that died in them and were subsequently buried under a blanket of clay or a cover of dripstone. Predatory animals and early humans alike sought shelter in caves and brought food with them to the eater, leaving bones that paleontologists have discovered.
It can be inferred that a condition that favors fossilization when volcanic ash falls to Earth is______.
选项
A、quick burial.
B、cold storage.
C、quick temperature change.
D、lack of water
答案
A
解析
本题是一个推断题,要求考生对文中的一段表述作出判断。
转载请注明原文地址:https://kaotiyun.com/show/VpJd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
Waterisakindofchemicalsubstance.
Aslongasherparentscanremember,13-year-oldKatieHarthasbeentalkingaboutgoingtocollege.Hermother,Tally,afinanc
Themostobviouspurposeofadvertisingistoinformtheconsumerofavailableproductsorservices.Thesecond【C1】______istos
Childrenwhogriptheirpenstooclosetothewritingpointarelikelytobeatadisadvantageinexaminations,【C1】______tothe
Childrenwhogriptheirpenstooclosetothewritingpointarelikelytobeatadisadvantageinexaminations,【C1】______tothe
TheBritishphilosopherandlogicianBertrandRusselloncewrote:"Mathematics,rightlyviewed,possessesnotonlytruth,butsu
WhatishappeninginAustralia’sagriculturalindustry?
TheissueofonlineprivacyintheInternetagefoundnewurgencyfollowingtheSept.11terroristattacks,sparkingdebateover
TheissueofonlineprivacyintheInternetagefoundnewurgencyfollowingtheSept.11terroristattacks,sparkingdebateover
Theorchidisuniquebecauseof______.Howmanyorchidseedsaretypicallypollinatedatonetime?
随机试题
行政规划的特征不包括()
A.促进肾小管对钙的重吸收B.促进骨液中的钙转运至血液内C.刺激破骨细胞活动,增强溶骨过程D.促进1,25-(OH)2-VD3的生成,增加肠对钙的吸收在PTH作用后几分钟内可引起血钙升高,其原因是
女,10个月。腹泻3d,加重2d。暗绿色水样便,每日10余次,量多、腥臭,伴高热、呕吐、尿少1d。查体:精神委靡,呈嗜睡状,前囟眼窝凹陷,皮肤弹性差,心音较低钝,双肺(-),腹较胀,肠鸣音正常,肝脾不大。粪检有大量脓细胞,血钠135mmol/L,血钾3.5
张某曾担任检察官8年,2003年12月辞职到某律师事务所担任专职律师。2004年4月,他担任一起刑事案件一审和上诉审的辩护人,由于谙熟刑事诉讼法,他从程序上的辩护意见被二审人民法院采纳,二审人民法院裁定案件发回重审。律师张某得到了刑事被告委托人的高度评价,
工程建设中安全管理的原则是安全第一,预防为主。()
一节美术活动结束了,每个小朋友都交上了自己的作品,今天画的内容是“冬天”这个主题,我又像往常一样,在美术课最后环节评价幼儿的作品,我把幼儿的一大堆作品放到自己的脚跟前,然后一张一张地评价幼儿的作品,这时,我拿出李怡旋小朋友的作品,一个劲地表扬她画得好看:“
在商品经济条件下,价值规律可以刺激商品生产者改进技术,改善经营管理,提高劳动生产率。这是由于个别企业率先提高劳动生产率可以——。
2012级企业管理专业的林楚楠同学选修了“供应链管理”课程,并撰写了题目为“供应链中的库存管理研究”的课程论文。论文的排版和参考文献还需要进一步修改,根据以下要求,帮助林楚楠对论文进行完善。为论文创建封面,将论文题目、作者姓名和作者专业放置在文本框
A、对对方感到不满B、表扬对方做得好C、不知道该怎么说D、对方做事有一套A“让我说你什么好啊”表示不满,不知道该说什么了,所以选择A。
A:Whatasurprise!Youchangedyourhairstyle.B:Yes,andanothersurprise.I’mgoingtogetmarriednextSaturday.A:______
最新回复
(
0
)