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
外语
A summary of the physical and chemical nature of life must begin; not on the Earth, but in the Sun; in fact, at the Sun’s very c
A summary of the physical and chemical nature of life must begin; not on the Earth, but in the Sun; in fact, at the Sun’s very c
admin
2012-04-23
20
问题
A summary of the physical and chemical nature of life must begin; not on the Earth, but in the Sun; in fact, at the Sun’s very center. It’s here that is to be found the source of the energy that the Sun constantly pours out into space as light and heat. This energy is liberated at the center of the Sun as billions upon billions of nuclei hydrogen atoms collide with each other and fuse together to form nuclei of helium, and, in doing so, release some of the energy that is stored in the nuclei of atoms. The output of light and heat of the Sun requires that some 600 million tons of hydrogen be converted into helium in the Sun every second. This the Sun has been doing for several thousands of millions of years.
The nuclear energy is released at the Sun’s center as high - energy gamma radiation, a form of electromagnetic radiation like light and radio waves only of very much shorter wavelength. This gamma radiation is absorbed by atoms inside the Sun, to be reemitted at slightly longer wavelengths. This radiation, in its turn, is absorbed and reemitted. At the energy filters through the layers of the solar interior, it passes through the X - ray part of the spectrum, eventually becoming light. At this stage, it has reached what we call the solar surface, and can escape into space, without being absorbed farther by solar atoms. A very small fraction of the Sun’s light and heat is emitted in such directions that, after passing unhindered through interplanetary space, it hits the Earth.
A simple magnifying glass, focusing the Sun’s rays, can scoarch, a piece of wood or set a scrap of paper on fire. Solar radiation can also be concentrated on a much larger scale. It can burn a hole through thick steel plate, for example, or simulate the thermal shock of a nuclear blast. It can, that is, with the help of a super reflector of the sort that has been set up by French scientists high in the Pyreness. The world’s largest solar furnace is a complex of nearly 20, 000 mirrors. It can concentrate enough sunlight to create temperatures in excess of 6000 degrees Fahrenheit.
The furnace’s appearance is as spectacular as its power. Its glittering eight - story - high reflector towers over very old houses. Anchored against a concrete office and laboratory building, the huge reflector consists of nearly 9000 separate mirrors. For the furnace to operate, these small mirrors must be adjusted so that their light will meet exactly at a focal point 59 feet in front of the giant reflector.
It can Be inferred from the passage that the Sun’s light travels ______.
选项
A、through solid objects in space
B、in many different directions
C、more slowly than scientists previously believed
D、further in summer than in winter
答案
B
解析
答案中C、D所涉及的内容在文章中没有提及,而太阳光通过太空时是穿过大气层,而没有通过太空中的固体物质。唯一可能的是太阳光在空间中不受拘束向多个方面传递。
转载请注明原文地址:https://kaotiyun.com/show/B3iO777K
0
专业英语八级
相关试题推荐
TheordinaryfamilyincolonialNorthAmericawasprimarilyconcernedwithsheerphysicalsurvivalandbeyondthat,itsownecon
InApril1995,ayoungChinesechemistrystudentatBeijingUniversitylaydyinginaBeijinghospital.Shewasinacoma,anda
Afullmoonwasshiningdownonthejungle.AccompaniedonlybyanIndianguide,theAmericanexplorerandarchaeologistEdward
Whichofthefollowingisthehighestformofliteraryexpression?
NationalParksInAmerican【1】,priorityisgiventotheamusementofthepublic.ButfortheNationalParks,thepriorityis【
Science,inpractice,dependsfarlessontheexperimentsitpreparesthanonthepreparednessofthemindsofthemenwhowatch
Anyphysicaltheoryisalwaysprovisional,inthesensethatitisonlyahypothesis:youcanneverproveit.Nomatterhowmany
Thecaseforcollegehasbeenacceptedwithoutquestionformorethanageneration.Allhighschoolgraduatesoughttogosaysc
Nomatterwhatyouwrite,yourmotherwillalwaysbelieveit’sabouther.SosaidauthorAnnBeattieafewyearsagoatabook
Thedarksmokethatcomesoutofstacksorfromaburningdumpcontainstinybitsofsolidorliquidmatter.Thesmokealsocont
随机试题
Itisnoteasyforfreshmentogetusedto______adormroomwithothers.
功血、黄体萎缩不全的临床表现及诊断是()
A.绍风穴B.大椎穴C.百会穴D.抢风穴E.环跳穴某犬,肩臂部受到冲撞后发病。证见站立时肘关节外展,运步时前脚尖着地,触诊前臂前外侧面反应迟钝。针刺治疗可选用的穴位是
在信息披露不充分的条件下,为了达到有效银行监管的目的,监管当局必须强化信息披露监控机制,包括()。
公民、法人或其他组织向人民法院提起行政诉讼后,无论人民法院是否已经受理,都可以同时申请行政复议。()
下列项目中,属于借款费用的有()。
为了做好文化和旅游、文物系统疫情防控工作,文化和旅游部积极主动印发并实施了一系列的通知。这些通知按照疫情发展的时间轴可以简单分为三个阶段:()。
组织结构确定、角色分配明确的群体称为()【江西师范大学2011】
若f(x)在x0点至少二阶可导,且则函数f(x)在x=x0处()
Inthissection,youareaskedtowriteanessaybasedonthefollowingchart.Inyourwriting,youshould1)interpretthechar
最新回复
(
0
)