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
26
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
蒸汽锅炉满水或缺水都可能造成锅炉爆炸。水位计是用于显示锅炉内水位的安全装置。下列
宜春温汤温泉属( )性质的矿泉。 A、碳酸氢钠 B、高温重碳酸钠弱碱 C
(1-2题共用题干) 男性49岁,腹胀黄疸8个月,查体腹部膨隆,肝脾肿大,移动
在吸毒的三级预防措施中,下列哪种不属于三级预防() A.戒毒治疗 B.康复治
能在HAT培养基生长繁殖的细胞是 A、小鼠脾细胞 B、小鼠骨髓瘤细胞
在处理有腐蚀性的物料或减压蒸馏系统中,对液、气量比较大的蒸馏或吸收操作,宜采用的
下列关于PFI和BOT的说法,正确的是()。
已满14周岁不满16周岁的人犯罪的是法定应当从轻或减轻处罚的情节。( )
患儿,男,1岁。发热1天,体温39℃,伴轻咳,在门诊就诊过程中突然发生惊厥,即刻给予吸氧,此刻止痉的药物首选A:苯巴比妥肌注B:地西泮肌注C:地西泮静推D
冬期土方回填每层铺土厚度应比常温施工时减少()。A.20%~25%B.25%~30%C.30%~35%D.35%~40%