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
Sunspots It’s not surprising that sunspots (太阳黑子) were observed by ancient astronomers (天文学家). The largest sunspots on the s
Sunspots It’s not surprising that sunspots (太阳黑子) were observed by ancient astronomers (天文学家). The largest sunspots on the s
admin
2009-05-21
86
问题
Sunspots
It’s not surprising that sunspots (太阳黑子) were observed by ancient astronomers (天文学家). The largest sunspots on the sun can be seen without a telescope. It was not until the invention of the telescope (望远镜) in the early 17th century, however, that systematic studies of sunspots could be undertaken. The great astronomer Galileo was among the first to make telescopic observations of sunspots.
Sunspots are regions of extremely strong magnetic fields (磁场) found on the sun’s surface. A sunspot has a dark central core known as the umbra. The umbra is surrounded by a dark ring called the penumbra, where the magnetic field, spreads outward. Sunspots appear dark because they are giving off less radiation. They are cooler than the rest of the sun’s surface.
Sunspots are frequently observed in pairs or in paired groups. The members of a spot pair are identified as the leading spot and the following spot. They are identified by their position in the pair in terms of the direction in which the sun rotates (旋转).
The number of sunspots at any one time varies. A large spot group may consist of as many as 10 groups and 300 spots across the sun. The number of spots changes in a fairly regular pattern called the sunspot cycle. The largest number occurs about every 11 years. At sunspot minimum, there are at most just a few small spots.
The average lifetime of an individual spot group is roughly one solar rotation, which is about 25 days. The most persistent large spots, however, can survive for two to three months.
选项
A、were made by ancient astronomers.
B、started in the early 17th century.
C、were made by Galileo only.
D、could be made without a telescope.
答案
B
解析
答案在第一段的第三句话。直到十七世纪早期发明了望远镜,对太阳黑子的系统研究才得以进行。所以和原文内容符合的只有B。
转载请注明原文地址:https://kaotiyun.com/show/6Yhd777K
本试题收录于:
职称英语理工类C级题库职称英语分类
0
职称英语理工类C级
职称英语
相关试题推荐
OnlyinFebruaryshouldattentionbepaidtochildren’soralhealth.Dentalandoraldiseasesarecommoninbothadultsandchi
A.fallasleepagainB.becomemoreenergeticthefollowingdayC.sleeplessthan7hoursD.confirmthoseseriousconsequen
Notallmemberstatesabidedbytheprincipletheyhadagreedonpreviously.
StudiesShowU.S.SpendingDoesn’tGetBestHealthTheUnitedStatesmayspendtwiceasmuchonhealthcareasotherrichc
Becausethesaleofbondsisaconvenientmeansofraisingcapital,corporationsoftenissuebondsaswellasstocks.
Domion’sPizza:TheHome-DeliveryLeaderDomino’sPizzaisthefastest-growingandsecond-largestpizza(烤比萨饼)chaininthe
EatHealthy"Cleanyourplate!"and"Beamemberoftheclean-plateclub!"JustabouteverykidintheUKhasheardthisf
EatHealthy"Cleanyourplate!"and"Beamemberoftheclean-plateclub!"JustabouteverykidintheUKhasheardthisf
ThepassageindicatesthatancienttreatmentsforinjuryanddiseasewereWhatdothemajorityofthepeopleintheworldusef
随机试题
A.间脑B.大脑半球C.桥脑D.延脑E.中脑昏迷时瞳孔极度扩大,脑损害水平定位在
A.圆三角形B.椭圆形C.钝圆角梯形D.四边形E.圆形下列牙齿的开髓洞形呈下颌磨牙
恶性程度最高的乳癌类型是
A.范德华力B.疏水性相互作用C.离子-偶极、偶极-偶极D.氢键E.电荷转移复合物抗疟药氯喹与疟原虫的DNA碱基对之间形成()。
短期政府债券具有违约风险小,流动性强、收入免税等特点。()
()是把课程计划付诸实践的过程,是达到预期课程目标的基本途径。
选择最恰当的一项填充空缺处,使之符合原图表的排列规律,此项是()。
Beesareinsects.TheyliveallovertheWorldexceptWhereitisverycold.Beesdonotlikeiceandsnow.Theyaretheonlyins
Whodidthemanspeakwiththisafternoon?
春节是中国最重要的节日。观看春节联欢晚会(theSpringFestivalGala)是中国人庆祝春节的一个重要组成部分。这个一年一度的晚会由中央电视台(CCTV)直播,从除夕之夜晚上8点开始,持续约4个小时。晚会节目丰富多彩,以音乐、舞蹈、喜剧和戏
最新回复
(
0
)