首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
下面有 3 篇短文,每篇短文后有 5 道题。请根据短文内容,为每题确定 1 个最佳选项。 Sunspots It’s not surprisi...
下面有 3 篇短文,每篇短文后有 5 道题。请根据短文内容,为每题确定 1 个最佳选项。 Sunspots It’s not surprisi...
admin
2020-12-24
44
问题
下面有 3 篇短文,每篇短文后有 5 道题。请根据短文内容,为每题确定 1 个最佳选项。
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 inventiion 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.
Sunsipots 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.
Sunspots are cooler than the rest of the sun’s surface because
选项
A they produce less energy,
B they are buried in the sun.
C they are far away from magnetic fields,
D they are close to magnetic fields.
答案
A
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/VbsQKKKQ
相关试题推荐
下面的短文有5处空白,短文后有6个句子,其中5个取自短文,请根据短文内容将其分别放回原有位置,以恢复文章原貌。 ADoctorintheHou...
下面的短文有5处空白,短文后有6个句子,其中5个取自短文,请根据短文内容将其分别放回原有位置,以恢复文章原貌。
下面的短文有5处空白,短文后有6个句子,其中5个取自短文,请根据短文内容将其分别放回原有位置,以恢复文章原貌。
下面的短文后有2项测试任务:(1)第23~26题要求从所给的6个选项中为第1~4段每段选择1个最佳标题;(2)第27~30题要求从所给的6...
下面的短文后有2项测试任务:(1)第23~26题要求从所给的6个选项中为第1~4段每段选择1个最佳标题;(2)第27~30题要求从所给的6...
下面的短文后有2项测试任务:(1)第23~26题要求从所给的6个选项中为第1~4段每段选择1个最佳标题;(2)第27~30题要求从所给的6...
下面的短文后有2项测试任务:(1)第23~26题要求从所给的6个选项中为第1~4段每段选择1个最佳标题;(2)第27~30题要求从所给的6...
下面的短文后有2项测试任务:(1)第23~26题要求从所给的6个选项中为第1~4段每段选择1个最佳标题;(2)第27~30题要求从所给的6...
下面的短文后有2项测试任务:(1)第23~26题要求从所给的6个选项中为第1~4段每段选择1个最佳标题;(2)第27~30题要求从所给的6...
下面的短文有5处空白,短文后有6个句子,其中5个取自短文,请根据短文内容将其分别放回原有位置,以恢复文章原貌。 TheToughGrassth...
随机试题
社区获得性肺炎,不需住院,无基础疾病的宜选 A.头孢唑啉 B.阿莫西林 C
关于三叉神经痛,错误的是 A.又称痛性抽搐 B.局限于三叉神经分布区 C.
关于健康教育计划设计原则,不正确的是()。
以下各个选项中,表述正确的有()。
下列对金属幕墙面板加工制作工艺的说法,符合规范要求的有()
氯丙嗪作用机制为() A.对心肌有奎尼丁样作用 B.使突触间隙的NA浓度下降
有的幼儿园在创设物质环境过程中,购买大量高价的成品玩具,追求高档,教师花费大量心血精心布置五彩缤纷的墙饰,甚至还买来一些名画进行装饰,环境的布置非常明显地...
肝病患者需要应用大环内酯类的酯化物抗感染时,应该A:短期口服或静脉给药B:长期用药应减量C:尽可能避免使用D:属于禁忌证E:谨慎使用
知识点:疝 男性,50岁,腹股沟三角突出半球形包快,易还纳,未进入阴囊,不透光,主要考虑为A.鞘膜积液B.隐睾C.股疝D.斜疝E.直疝
橘红丸适用于A.燥咳少痰,质黏难出B.咳嗽痰多,色黄黏稠C.咳嗽痰黄,咽喉肿痛D.发热恶寒,咳喘气急E.阴虚劳嗽,咳痰带血