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
2016-10-25
54
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.
Harold Urey and Stanley L. Miller did their experiment in order to______.
选项
A、find out what had happened on the Earth 4 billion years ago
B、simulate bolts of lightning on the ancient Earth
C、dissolve some new chemicals
D、analyze a liquid
答案
A
解析
文章第三段…Harold Urey and Stanley L.Miller did a very simpleexperiment to find out what had happened on the primitive Earth及第二句中的4billion years ago,由此可知这里的primitive Earth是指4 billion years ago,所以A为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/dVHC777K
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
Ifyouliveinalargecity,youarequitefamiliarwithsomeoftheproblemsofnoise,butbecauseofsomeofitsharmfuleffec
Byadoptingafewsimpletechniques,parentswhoreadtotheirchildrencangreatlyincreasetheirchildren’slanguagedevelopm
Everyoneknowsthatlazinessisnotgood.Wehaveprobablyallbadlecturestellingthatlazinessisimmoral,thatitiswastefu
Theprogrammerwasalwaysbusyinan______way,spendinghoursaccompanyingnothing.
Honeybeescannotlivealone.Theirbodystructureandinstinctsequipthemforlifeinacolony(群居)orcommunity,wheretheyhave
Themostimportantstartingpointforimprovingtheunderstandingofscienceisundoubtedlyanadequatescientificeducationat
Areallypowerfulspeakercan______thefeelingsoftheaudiencetothefeverofexcitement.
Thefamousprofessorgaverequired______intraditionalmusicandalsocoachedyoungorchestralplayers.
我提议咱们会后马上去办公室找史密斯教授,邀请他参加我们的英语晚会。
Thegovernmentshould______(把减少失业放在首要的位置)intimeoffinancialcrises.
随机试题
出版工作的文化性,体现在()等方面。
维生素A含量丰富的食物是
A.冲击触诊法B.双手触诊法C.深部滑行触诊法D.浅部触诊法E.间接叩诊法大量腹水检查用
成人的主要造血器官是()。
某施工单位承接了一条二级公路的隧道施工项目,该隧道主要穿越砂层泥岩和砂岩,岩层节理、裂隙发育,富含裂隙水。隧道全长800m,设计净高5m,净宽12m,为单洞双向行驶的两车道隧道。施工单位针对该项目编制了专项施工方案,其中包括工程概况、编制依据、劳动力计划
下列各项中属于资金退出的是()。
证券公司代销金融产品,代销的金融产品具有()特征的,证券公司应当以简明、易懂的文字,向客户作出有针对性的书面说明,同时详细披露金融产品的风险特征与客户风险承受能力的匹配情况,并要求客户签字确认。I.流动性较低的Ⅱ.透明度较低的
措施项目是指为完成工程项目施工、发生于该工程施工准备和施工过程中的()项目。
按照房地产()细分,可把房地产市场分为房地产一级市场、房地产二级市场和房地产三级市场。
强权政治
最新回复
(
0
)