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
89
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://www.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
Acrowdgatheredtoseewhathadhappened.
OnlyinFebruaryshouldattentionbepaidtochildren’soralhealth.Somechildrenhaveneverseenadentistbeforestartingsc
OnlyinFebruaryshouldattentionbepaidtochildren’soralhealth.Boysmissmoreschoolhourseachyearduetodental-relate
EatHealthy"Cleanyourplate!"and"Beamemberoftheclean-plateclub!"JustabouteverykidintheUShasheardthisfro
BreastCancerDeathsRecordLowThenumberofwomendyingfrombreast(乳房)cancerhasfallentoarecordlowbydroppingund
EatHealthy"Cleanyourplate!"and"Beamemberoftheclean-plateclub!"JustabouteverykidintheUKhasheardthisf
随机试题
某市今年进入夏天以来,不少市民发现蚊子越来越多,简直无法控制。之所以出现这种情况,有医学专家认为,由于该市今年气温比去年同期要高,而高温天气有利于蚊子的生长,这就使得今年的蚊子比往年多。下列选项中,最能削弱该专家观点的是()。
为个人学习、研究使用他人已经发表的作品的,不需要支付报酬,但应当指明()。
已知某普通股的13值为1.2,无风险利率为6%,市场组合的必要收益率为10%,该普通股的当前市价为10.5元/股,筹资费用为0.5元/股,股利年增长率长期固定不变,预计第一期的股利为0.8元,按照股利增长模型和资本资产定价模型计算的股票资本成本相等,则该普
金融市场具有的功能有()
在社会主义市场经济条件下,公共财政的职能包括()。
“举一反三”“闻一知十"属于迁移的()
下列措施属于政府发挥社会职能的是()。
英国科学家研制出了一种专门清除太空垃圾的人造卫星,这就是我们所说的太空“清洁工”,它可以帮助解决太空垃圾这个令人头疼的问题。太空“清洁工”的质量只有6千克,制造和发射的费用,不到100万美元。别看它个儿不大,本领可不小,它装有4台摄像机,用于搜索上下、左右
(Thesimplest)kindofplant,(alike)thesimplestkindofanimal,(consistsof)(onlyone)cell.
Passage1
最新回复
(
0
)