首页
登录
职称英语
When we accept the evidence of our unaided eyes and describe the Sun as a y
When we accept the evidence of our unaided eyes and describe the Sun as a y
游客
2025-03-15
36
管理
问题
When we accept the evidence of our unaided eyes and describe the Sun as a yellow star, we have summed up the most important single fact about it--at this moment in time. It appears probable, however, that sunlight will be the color we know for only a negligibly (微不足道的) small part of the Sun’s history.
Stars, like individuals, age and change. As we look out into space, we see around us stars at all stages of evolution. There are faint blooded dwarfs so cool that their surface temperature is a mere 4,000 degrees Fahrenheit; there are scaring ghosts blazing at 100,000 degrees Fahrenheit and almost too hot to be seen, for the great part of their radia-tion is in the invisible ultraviolet range. Obviously, the "daylight" produced by any star depends on its temperature; today (and for ages to come) our Sun is at about 10,000 de-grees Fahrenheit, and this means that most of the Sun’s light is concentrated in the yellow band of the spectrum, falling slowly in intensity toward both the longer and shorter light waves.
That yellow "hump" will shift as the Sun evolves, and the light of the day will change accordingly.
It is natural to assume that as the Sun grows older, and uses up its hydrogen fuel-which it is now doing at the spanking rate of half a billion tons a sec-ond-it will become steadily colder and redder.
[br] What is the passage mainly about?
选项
A、Faint dwarf stars.
B、The evolution cycle of the Sun.
C、The Sun’s fuel problem.
D、The dangers of invisible radiation.
答案
B
解析
本题为主旨题。本文主要是谈太阳的演化周期,所以为B。对A项为微红的矮星、C项为太阳的燃料问题,都只是一带而过,不可作为本文的中心议题。本文没有谈及D项的不可见辐射的危险。
转载请注明原文地址:https://tihaiku.com/zcyy/3998026.html
相关试题推荐
WhenweaccepttheevidenceofourunaidedeyesanddescribetheSunasay
WhenweaccepttheevidenceofourunaidedeyesanddescribetheSunasay
WhenweaccepttheevidenceofourunaidedeyesanddescribetheSunasay
Ajudgemustbe______whenweighingevidence.A、interestedB、disinterestedC、sep
______Iacceptthatheisnotperfect,Idoactuallyliketheperson.A、WhileB、
______andhappy,Tonystoodupandacceptedtheprize.A、SurprisingB、Surprised
Ifhehadapplied(byAugust)15,theuniversity(hadaccepted)(him)(this)sem
Thereisagreatdealofevidence______thatmusicactivitiesengagedifferent
Auniversitygraduatedescribedasa"respectableandintelligent"womanis
Auniversitygraduatedescribedasa"respectableandintelligent"womanis
随机试题
Beijingskywatcherswillbeexcitedbecause______.[br]Thetwomoreexciting
Aestheticthoughtofadistinctivelymodernbentemergedduringthe18thc
Prevailingmythologyhasitthatcreativityistheexclusivedomainofartist
HowlongdidthespeakerstayinHollywoodlastChristmas?Shestayedtherefor
[originaltext]W:Right,Iguessyouhavesomeideasforourpromotion.M:Well,f
影响放射免疫测定的主要因素不包括A.抗原的纯度B.抗血清的亲和力和特异性C.结合
2020年1—4月份,规模以上煤炭开采和洗选业营业成本比石油和天然气开采业约
随着人类生命的延长和对生活健康品质的个性化需求,制造业正在从以满足人类对交通和能
缩泉丸的注意事项是A.湿热痢疾、湿热泄泻者忌用。忌食生冷、油腻食物 B.肝经湿
下列关于船舶吨税的表述中,正确的是()。A.吨税只对外国籍船舶征收 B.吨税
最新回复
(
0
)