首页
登录
职称英语
For many years, scientists couldn’t figure out how atoms and molecules combi
For many years, scientists couldn’t figure out how atoms and molecules combi
游客
2024-07-08
21
管理
问题
For many years, scientists couldn’t figure out how atoms and molecules combined to make living things. Plants, fish, dinosaurs, 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 have energy and can reproduce, while the chemicals on the Earth 4 billion years ago were lifeless.
After years of study, scientists figured out that living things, including human bodies, are basically made of amino acids, nucleotide bases, lipids and water. How could such complicated molecules have been formed and have started to interact in the primitive soup? Scientists were stumped.
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, and put in some of the same gases that were present in the atmosphere 4 billion years ago—water vapour, ammonia, carbon dioxide, methane, and hydrogen.
Then they shot an electric spark through the gases to simulate bolts of lightning on the ancient Earth, circulated the gases through some water, sent them back for more sparks, and so on. After several days, the water that the gases had been bubbling through 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.
选项
A、4 billion years ago.
B、After seven days.
C、Many years ago.
D、In 1953.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3667718.html
相关试题推荐
_______enoughtime,butIcouldn’tdoitbetter.A、IwasgivenB、GivenC、Tobeg
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
Scientistsarebuildingtheworld’sfirstthinkingrobot.It’strue.Some
[originaltext]M:Theadvertisementsonthesubwaysareboring.W:Icouldn’tag
Ifyoucouldn’tkeepthe(appoint)________,pleaseinformusasearlyaspossib
(watch)______byacrowdofpeople,Charlesfeltembarrassedandcouldn’tsay
随机试题
ThePeakTimeforEverythingA)Couldyoupackmoreinto
什么是公债?公债有哪些特征?公债的主要作用是什么?
下列选项说法不正确的是()。A.基于BIM的室外声学分析流程为首先建立BIM模型
《依法治教实施纲要(2016--2020年)》中指出,适时启动《教师法》《高等教
下列属于房地产投资特点的有()。A.投资选择的多样性 B.投资价值的附加性
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性: A.如
阅读下列材料,回答教师遇到如下情况应采取的措施。 贝贝穿了一件粉红色的外套,
广记公司是一家卤制品生产企业。该公司凭借其长期积累形成的原料配制秘方和生产工艺
在项目法人合同管理注意事项中,下列说法正确的是()。A.材料和设备供应是买
监理招标应当具备的条件包括()。A.初步设计已经批准 B.技术经济指标已基本
最新回复
(
0
)