首页
登录
职称英语
According to the best evidence gathered by space probes and astronomers, Mars
According to the best evidence gathered by space probes and astronomers, Mars
游客
2023-12-18
39
管理
问题
According to the best evidence gathered by space probes and astronomers, Mars is an inhospitable planet, more similar to Earth’s Moon than to Earth itself a dry, stark, seemingly lifeless world. Mars’ air pressure is equal to Earth’s at an altitude of 100,000 feet. The air there is 95% carbon dioxide. Mars has no ozone layer to screen out the Sun’s lethal radiation. Daytime temperatures may reach above freezing, but because the planet is blanketed by the mere wisp of an atmosphere, the heat radiated back into space. Even at the equator, the temperature drops to -50℃ (-6(YF) at night. Today there is no liquid water, although valleys and channels on the surface show evidence of having been carved by running water. The polar ice caps are made of frozen water and carbon dioxide, and water may be frozen in the ground as permafrost.
Despite these difficult conditions, certain scientists believe that there is a possibility of transforming Mars into a more Earth-like planet. Nuclear reactors might be used to melt frozen gases and eventually build up the atmosphere. This in turn could create a "greenhouse effect" that would stop heat from radiating back into space. Liquid water could be thawed to form a polar ocean. Once enough ice has melted, suitable plants could be introduced to build up the level of oxygen in the atmosphere so that, in time, the planet would support animal life from Earth and even permanent human colonies. "This was once thought to be so far in the future as to be irrelevant," said Christopher McKay, a research scientist at the National Aeronautics and Space Administration. "But now it’s starting to look practical. We could begin work in four or five decades."
The idea of "terra-forming" Mars, as enthusiasts call it, has its roots in science fiction. But as researchers develop a more profound understanding of bow Earth’s ecology supports life, they have begun to see how it may be possible to create similar conditions on Mars. Don’t plan on homesteading on Mars any time soon, though. The process could take hundreds or even thousands of years to complete, and the cost would be staggering. [br] Which of the following is NOT listed by the author as a characteristic of the planet Mars that would make colonization difficult?
选项
A、There is little liquid water.
B、Daytime temperatures are dangerously high.
C、The Sun’s rays are deadly.
D、Nighttime temperatures are extremely low.
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3282901.html
相关试题推荐
Accordingtothenews,whatmakesthiscreditcarddifferentfromconventionalo
Accordingtothepassage,whichofthefollowinggroupsofpeoplemightbeviewe
Accordingtothepassage,devolutionwasmainlymeantto______.[br]Whichoft
Accordingtothepassage,thenewcollege-entrancesystemisdesignedto______.
Accordingtothepassage,thenewcollege-entrancesystemisdesignedto______.
Accordingtothepassage,thenewcollege-entrancesystemisdesignedto______.
Morethanonevariant,whichcanrealizesomemorphemesaccordingtothepositio
What’sthemainideaofthefirstthreeparagrahs?[br]Accordingtotheauthor,
Itcanbeinferredfromthefirstparagraphthatcosmologists[br]Accordingto
Itcanbeinferredfromthefirstparagraphthat[br]AccordingtoJamilSalmi,
随机试题
ThefirsttimeanybodyknewaboutDutchmanFrankSiegmundandhisfamilywa
Henry’sjobwastoexaminecarswhichcrossedthefrontiertomakesure【C1】
Overhalftheworld’speoplenowliveincities.Thelatest"GlobalReporto
[originaltext]W:So,whatcanIdoforyoutoday?M:Well,urn,[6]nextmonthi
Alectureisnot【D1】______Useabbreviations,symbols,numbersandsoon
[audioFiles]audio_eusm_j73_001(20082)[/audioFiles]A、Childrengettheirpersonal
运输企业向顾客提供服务的技术质量包括()。A.技术手段 B.技术设备 C
血燥生风的病因是A.生血不足或失血过多 B.久病耗血或年老精亏 C.产后恶露
在影响操作风险的因素中,交易/定价错误属于内部流程类的因素。它是指()。A.银行
下列关于甲公司与客户乙公司签订的合同中,对单项履约义务认定正确的有( )。A.
最新回复
(
0
)