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
专升本
For many years, scientists couldn’t figure out how atoms and molecules(分子)on the Earth combined to make living things. Plants, f
For many years, scientists couldn’t figure out how atoms and molecules(分子)on the Earth combined to make living things. Plants, f
admin
2014-05-25
39
问题
For many years, scientists couldn’t figure out how atoms and molecules(分子)on the Earth combined to make living things. Plants, fishes, dinosaurs(恐龙), and people are made of atoms and molecules, but they are put together in a more complicated way than the molecules in the primitive ocean. What’s more, living things, that have energy and can reproduce on the Earth four billion years ago were lifeless.
After years of study, scientists figured out that living things, including human bodies, are basically made of amino acids and nucleotide(氨基酸与核苷酸)bases. These are molecules with millions of hydrogen(氢), carbon(碳), nitrogen(氮), and oxygen atom. How could such complicated molecules have been formed in the primitive soup? Scientists were stumped(难住).
Then, in 1953, two scientists named Harold Urey and Stanley L. Miller did a very simple experiment to find out what had happened on the primitive Earth. They set up some tubes and bottles in a closed loop(线圈), and put in some of the same gases that were present in the atmosphere four billion years ago: water vapor, carbon dioxide(二氧化碳), methane(甲烷), and hydrogen.
Then they shot an electric spark through the gases to simulate(模拟)bolts(闪电)of lightning on the ancient Earth, circulated the gases through some water, sent them back for more sparks, and so on. After seven days, the water that the gases had been bubbling(起跑)through had turned brown. Some new chemicals were dissolved in it . When Miller and Urey analyzed the liquid, they found that it contained amino acids—the very kind of molecules found in all living things.
When did scientists come to realize how the atoms and molecules on the Earth combined to make living things?
选项
A、Four billion years ago.
B、In 1953.
C、After seven days.
D、Many years later.
答案
B
解析
文章第三段Then,in 1953,two sciemists named Harold Urey and StanleyL.Miller did a very simple experiment to find out what had happened on theprimitive Earth.1953年,两位科学家做实验试图找出远古地球上所发生的一切,即人类和生物是怎样形成的,也即1953年起,人类才开始明白地球上的生物是怎祥由原子和分子结合而产生的,所以B为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/0FUC777K
本试题收录于:
英语题库普高专升本分类
0
英语
普高专升本
相关试题推荐
Ingeneral,theancientRomanswereapracticalpeople.TheycaredlessaboutphilosophyandpuremathematicsthantheGreeksdi
TheAmericansandtheBritishnotonlyspeakthesamelanguagebutalso______manysocialcustoms.
Whydowelaugh?Foryearsscientistshaveaskedthemselvesthisquestion.Nootheranimalslaughandsmile,onlyhumanbeings.
Scientistsareworkingonanelectronicdevice,whichcouldmakelifeeasierforthepeople.
Mostpeopleretirefromworkbetweentheagesof60and65.Thishas【31】consequences,oneeconomicand【32】psychological.Eco
Telephone,television,radio,andtheInternethelppeoplecommunicatewitheachother.Becauseofthesedevices,ideasandnews
A、Studentevaluationsofteachersarepopularbecausetheyareveryaccurate.B、Instudentratings,studentsshouldnotbeasked
Hehasmadeanotherwonderfuldiscovery,______ofgreatimportancetoscienceandman.
Thechildrenlookedupastheplanespassed______.
—What’sthatnewly-builtbuilding?—______thestudentshaveout-of-classactivities,suchasdrawingandsinging.
随机试题
当冷却塔与周围女儿墙的间距不能满足设备技术要求时。女儿墙的设计应采取以下哪种主要措施?[2009年第84题]
智能化系统的电动调节阀安装前,应检查的内容有()。
A、$40.B、$30.C、$20.D、$10.C
教学评价能调动师生的积极性和创造性,提高学生的学习兴趣,这体现了教学评价的()。
义字成为记录文化的有效工具是从意音文字开始的。美索不达米亚的钉头字、埃及的圣书字、中美洲的玛雅字、中国汉字等都是意音文字。_________。现在,绝大部分著名的意音文字都成为历史陈迹了,只有汉字,作为意音文字在今天的世界上巍然独存。填入划横线部分最恰当的
研究人员发现,如果手机处在视线内或者容易触及的地方,人的注意力会下降,完成任务时表现也会更差,因为大脑会忙着应付一件事:不要拿起手机。沃德称:“即使智能手机只是存在于那里,也足以削弱人的感知能力。”最不能支持上述结论的是()。
设A为三阶矩阵,且|A|=4,则|(A*/2)-1|=________.
It’sgenerallyacceptedthatthereisacorrelationbetweenachild’seducationalattainmentandafamily’spovertylevel,butn
A、Howtoattachfilestoemails.B、HowtogetaccesstotheInternet.C、HowtousetheInternetmoreefficiently.D、Howtoinsta
Becausesomanypeopleintheirteensandearly20sareincreasinglysocializing—accessibletoeachothereveryminuteoftheda
最新回复
(
0
)