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
27
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 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.
The leading spot and the following spot are the names of
选项
A two large sunspots.
B a large spot and a small spot.
C the two spots in a spot pair.
D the central core and the ring around it.
答案
C
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/IlsQKKKQ
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。 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
前方牵引矫治器主要用于矫治 A.生长发育阶段上颌发育不足的Ⅲ类错牙合 B.生
主张教育是学生自我实现的过程,这种教育质量观是()。
如果甲比乙多20%,乙比丙多20%,则甲比丙多百分之多少?
以下各项中不能反映期货合约(futures)与远期合约(forwards)差异点
1,13,45,169,()A.443B.889C.365D.701
国产HXD1型电力机车在短路和其它故障情况下,在达到最大支路电流前自动封锁相关模块的触发脉冲。
患儿男,5岁。因脸色苍白就诊。诉平素饮食规律,但间常有上腹痛,查体:神清,皮肤巩膜无黄染,口唇苍白,心肺无异常,肝右肋下1.5cm,脾左肋下1.5cm,实...
对支气管平滑肌β2受体有较强选择性的平喘药是()A:茶碱B:肾上腺素C:异丙肾上腺素D:沙丁胺醇E:色甘酸钠
下列现代企业部门划分的类型中,有利于发挥专用设备效益、人员技能和专业知识的是()组织结构。A.职能部门化B.产品部门化C.区域部门化D.过程部门化
税务师在2020年4月对某公司2019年度纳税情况进行审核,发现该公司多摊销了租赁办公室的装修费30000元,若该公司2019年度决算报表已编制,对该项费...