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
Reading According to the controversial sunspot theory, great storms on the surface of the Sun hurl streams of solar particles in
Reading According to the controversial sunspot theory, great storms on the surface of the Sun hurl streams of solar particles in
admin
2018-06-21
52
问题
Reading
According to the controversial sunspot theory, great storms on the surface of the Sun hurl streams of solar particles into space and eventually into the atmosphere of our planet, causing shifts in the weather on the Earth and interference with radio and television communications.
A typical sunspot consists of a dark central umbra, a word derived from the Latin word for shadow, which is surrounded by a lighter penumbra of light and dark threads extending out from the center like the spokes of a wheel. Actually, the sunspots are cooler than the rest of the photosphere, which may account for their apparently darker color. Typically, the temperature in a sunspot umbra is about 4000 K, whereas the temperature in a penumbra registers 5500 K, and the granules outside the spot are 6000 K.
Sunspots range in size from tiny grains to complex structures with areas stretching for billions of square miles. About 5 percent of all sunspots are large enough so that they can be seen from Earth without instruments; consequently, observations of sunspots have been recorded for thousands of years. They have been observed in arrangements of one to more than one hundred spots, but they tend to occur in pairs. There is also a marked tendency for the two spots of a pair to have opposite magnetic polarities. Furthermore, the strength of the magnetic field associated with any given sunspot is closely related to the spot’s size.
Sunspots have also been observed to occur in cycles, over a period of eleven years. At the beginning of a cycle, the storms occur between 20 and 40 degrees north and south of the equator on the Sun. As the cycle continues, some of the storms move closer to the equator. As the cycle diminishes, the number of sunspots decreases to a minimum, and they cluster between 5 and 15 degrees north and south latitude.
Although there is no theory that completely explains the nature and function of sunspots, several models show scientists’ attempts to relate the phenomenon to magnetic field lines along the lines of longitude from the north and south poles of the Sun.
Why are solar particles hurled into space?
选项
A、Undetermined causes on Earth
B、Disturbances of wind on the Sun
C、Small rivers on the surface of the Sun
D、Changes in the Earth’s atmosphere
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/WDfO777K
0
托福(TOEFL)
相关试题推荐
Whatinformationwasgivenbyeachwriter?ChooseyouranswersfromtheboxandwritethelettersA-FnexttoQuestions24-27.A
Completetheformbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswer.Pinder’sAnimal
Labeltheplanbelow.Writethecorrectletter,A-l,nexttoquestions16-20Whereinthemuseumarethefollowingplaces?Key
Completethenotesbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswerENVIRONMENTALCHANGEDISCUSSIONInSouthe
Completethenotesbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswerENVIRONMENTALCHANGEDISCUSSIONInSouthe
Completethenotesbelow.WriteNOMORETHANTWOWORDSAND/ORANUMBERforeachanswerENVIRONMENTALCHANGEDISCUSSIONInSouthe
Choosethecorrectletter,A,BorC.Thecoursehasimprovedtheenvironmentsince
ENDANGEREDSPECIESAlthoughwecannotdoanythingabouttheplantsandanimalsthatarealready【31】________,wecandosomething
AustralianAboriginalArtAncientartrockandbarkpaintingsanddrawings【L31】______________decorationso
AustralianAboriginalArtAncientartrockandbarkpaintingsanddrawings【L31】______________decorationso
随机试题
社会管理
市场调查就是要了解市场,搞清楚市场需求和市场供应两方面的情况。()
新生儿期的保健护理重点为:
一般保证是指在建设项目筹资经济活动中,在保证合同中约定,债务人不能履行债务时,由()来承担保证的责任。
一般纳税企业缴纳上月增值税的会计分录应为()。
根据反垄断法律制度的规定,在经营者集中附加限制性条件批准制度中,监督受托人应当符合的要求有()。
甲养殖场在A市的北郊,占地约4800平方米。2005年1月,甲得知该市将对城北进行城市规划,道路要从其养殖场中心通过,占去养殖场土地面积1500平方米。于是甲在没有向A市国土局办理申请用地手续的情况下,擅自以拆除其中养鸡场为名,与私人签订了协议.将20户住
即使在古代,规模生产谷物的农场,也只有依靠大规模的农产品市场才能生存,而这种大规模的农产品市场意味着有相当人口的存在。因为中国历史上只有一家一户的小农经济,从来没有出现过农场这种规模生产的农业模式,因此,现在考古所发现的中国古代城市,很可能不是人口密集的城
IthasbeenahundredyearssincethelastbigoneinCalifornia,the1906SanFranciscoearthquake,whichhelpedgive(1)_____
Whenprehistoricmanarrivedinnewpartsoftheworld,somethingstrangehappenedtothelargeanimals:theysuddenlybecameex
最新回复
(
0
)