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
49
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/Y8sQKKKQ
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。 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。 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。 ADoctorinthe...
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
某一级耐火等级的工业建筑,地上4层,地下1层,层高均为5.5m,每层建筑面积50
心律失常患者用药治疗期间应该禁用的是()
房地产估价原则是为了使不同的房地产估价师对房地产估价的基本前提有认识上的一致性,
股票交易和债券交易中的“一手”分别指()。
下列财政支出项目中,属于消费性支出的是( )。
阵发性睡眠性血红蛋白尿症的筛选试验是
住房商品化就意味着将住房推向市场,主要依靠市场调节来解决住房问题,同时也就意味着
哪项不是黄花蒿的性状鉴别特征A:茎方形,上部多分枝B:表面黄绿色或黄棕色,具纵棱线C:叶互生D:质略硬,断面中部有髓E:香气特异,味微苦
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。 CentersoftheGreatEuropeanCi...
以下关于护理保险的说法,正确的是()。 A.患有老年痴呆的人由于能完成一些日常活动,故不属于护理保险的保障人群 B.护理保险基本上全由商业保险公司提...