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
The temperature of the sun is more than 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than sixteen milli
The temperature of the sun is more than 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than sixteen milli
admin
2009-05-15
68
问题
The temperature of the sun is more than 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than sixteen million degrees at the center. The sun is so much hotter than the earth that matter can exist only as a gas, except at the core. In the core of the sun, the pressures are so great against the gases that, despite the high temperature, there may be a small solid core. However, no one really knows, because the center of the sun can never be directly observed.
Solar astronomers do know that the sun is divided into five layers or zones. Starting at the outside and going down into the sun, the zones are the corona, chromosphere , photosphere, convection and the sun has no solid surface, so it is difficult to tell where the atmosphere ends and the main body of the sun starts.
The sun’s outermost layer begins about 10,000 miles above the visible surface and goes out ward for millions of miles. This is the only part of the sun that can be seen during an eclipse such as the one in February 1979. At any other time, the corona can be seen only when special instruments are used on cameras and telescopes to shot out glare of the sun’s rays.
The corona is a bright, pearly white, filmy light, about as bright as the full moon. Its beautiful
rays are a sensational sight during an eclipse. The corona’s rays flash out in a brilliant fan that has wispy (纤细的) spikelike rays near the sun’s north and south poles. The corona is thickest at the sun’s equator.
The corona rays are made up of gases streaming outward at tremendous speeds and reaching a temperature of more than two million degrees Fahrenheit. The rays of gas thin out as they reach the space around the planets. By the time the sun’s corona rays reach the earth, they are weak and invisible.
选项
A、how the sun evolved
B、the structure of the sun
C、why scientists study the sun
D、the distance of the sun from the planets
答案
B
解析
从文章第二段首句:Solar astronomers do know that the sun is divided into five layers or zones.得知。故本题答案为B。
转载请注明原文地址:https://www.kaotiyun.com/show/dUyd777K
本试题收录于:
公共英语二级笔试题库公共英语(PETS)分类
0
公共英语二级笔试
公共英语(PETS)
相关试题推荐
【B1】【B12】
【B1】【B7】
ThefirstsentenceinParagraph1means______.Thebesttitleforthispassageis______.
ThefirstsentenceinParagraph1means______.Somefamiliesgatherclosertoeachotherathomethanothersbecause______.
Thefirstparagraphismainlyabout______.Whatistheshypeople’sreactiontopraise?
WhydidElizabethsaytoherfather"But,Dad,youcan’tbehealthyifyouaredead"?Accordingtothetext,tobe"throwncle
Nowthatmanhasactuallylandedonthesurfaceofthemoon,hehaslearnedmanynewthingsaboutit.Butonethingmanknewbef
Thefirstparagraphtellsmainlyabout______.Thewriterofthepassageperhapsis______.
WhydidElizabethsaytoherfather,"But,Dad,youcan’tbehealthyifyou’redead"?Whatistheadvicegiveninthetext?
Maybeten-year-oldElizabethputitbestwhenshesaidtoherfather,"But,Dad,youcan’tbehealthyifyou’redead."Dad,
随机试题
10个月小儿,双胎之一,因间断腹泻、食欲不佳,体重不增就诊。查体:欠活泼,体重7kg,身长74cm,腹部皮下脂肪0.4cm,两眼近角膜外侧缘有结膜干燥斑。次日晨患儿突然神志不清,面色苍白,脉搏减慢,呼吸暂停。该患儿最可能为
IgV区
患儿8岁,女。素有哮喘,症见咳嗽痰盛,食少脘痞,面黄欠华,大便不实,肌肉瘦弱,倦怠乏力,苔少色淡,脉缓无力。治疗首选方剂为
正常人体温中等度热
票据丧失后,失票人可以采取的补救措施包括()。
根据《标准施工招标文件》中“通用合同条款”的规定,质量保证金的计算额度应包括()。
我国QDⅡ基金产品的特点不包括()。
建设工程目标控制在施工招标阶段的任务不包括()。
阅读材料:内容选自人民教育出版社普通高中课程标准实验教科书(化学1必修)第一章第二节第一部分“物质的量的单位——摩尔”。2.化学计量在试验中的应用在化学实验室做实验时,取用的药品无论是单质还是化合物,都是可以用器具称量的。而物质问发生的化学反应是原子,
一个窗体上有两个文本框,其放置顺序分别是:Text1,Text2,要想在Text1中按"回车"键后焦点自动转到Text2上,需编写的事件是( )。
最新回复
(
0
)