首页
登录
职称英语
The old belief that the universe never changes is quite wrong. Even before th
The old belief that the universe never changes is quite wrong. Even before th
游客
2025-03-30
24
管理
问题
The old belief that the universe never changes is quite wrong. Even before the invention of the telescope, astronomers noticed that bright stars suddenly appear in the sky, and then later disappear.【R1】______In fact we now know that they are really old stars which are slowly dying. A recent case of a nova occurred in 1918, and one of the few people who saw this was the American astronomer Edward Barnard. He was driving along in a car, occasionally looking up into the sky. Suddenly he noticed a star that he had never seen before, and exclaimed, "That star should not be there!" He was in fact watching the explosion of a nova.
【R2】______As they do so, they let out huge clouds of material. Sometimes as large as the earth, and these explode into space at a speed of about 8, 000, 000 kilometers per hour. When this happens, the hotter parts of the star become visible, and this is why novae are so bright. Although the explosions are huge on a human scale, they only consume a small part of the dying star’s energy.
【R3】______Indeed, there are even some stars which explode once a fortnight.
There are other old stars which do not die slowly, but are completely destroyed by one great explosion.【R4】______The explosion of a supernova is equivalent to about a million, million, million, million hydrogen bombs going off at the same time. Just before the explosion the star’s density become very great and it spins at a very high speed. A matchbox of material taken from the star at that time would weigh about 1,000 tons, and the star would be turning at about 16,000,000 kilometers per hour.【R5】______One supernova which Chinese astronomers observed in 1054 can still be seen by us today. It has been shining for at least nine hundred years.
A. Novae are old stars which are slowly dying.
B. They are known as " supernovae."
C. The death is a slow one, and the star may continue to explode for thousands of years.
D. The explosion of a supernova is like a cosmic bomb.
E. The explosion itself occurs suddenly, in the space of a minute, but the supernova continues to shine long after the event.
F. These stars were called "novae" because they were thought to be new. [br] 【R2】
选项
答案
A
解析
本题的答题要点是把握文章第二段的主要内容,它描述了新星的衰落过程。空格后一句中的“so”可以是答题的线索词。
转载请注明原文地址:https://tihaiku.com/zcyy/4019605.html
相关试题推荐
rathercrawlitlittlebeforealthough
rathercrawlitlittlebeforealthough
rathercrawlitlittlebeforealthough
rathercrawlitlittlebeforealthough
rathercrawlitlittlebeforealthough
rathercrawlitlittlebeforealthough
rathercrawlitlittlebeforealthough
rathercrawlitlittlebeforealthough
The______ofcomputertechnologyhasledtomajorchangesinoursocialandfamil
ManychangesaretakingplaceinAmericans’foodstyles.【T1】TheUnitedStat
随机试题
Strongemotionsareusually【B1】______nonverbally:Bygestures,bodyposture,
Congresshasdecreedthatthepresentlaw_____.A、bemaintainedB、weremaintained
说明:假设你是青岛大学外语学院的张涵教授,现在需要给北京大学的李浩教授写一封邀请函,邀请他作一个讲座。时间:3月17日内容:1.发出诚挚邀请;2.讲座时
预先危险性分析法的特点包括( )。A.可以对新材料、新结构、新工艺存在的危险性
综合运输网布局,实质上就是建立()。A.国际运输体系 B.综合运输体
企业生产的产品没有图家、行业.准的,应当制定企业标准,作为组织生产的依据。()
A.MRI血管造影 B.水成像 C.MRI对比增强检查 D.功能性MRI成
财务报告分析的主要形式包括()A:内部分析与外部分析B:趋势分析、现状分析与潜
我国银行间外汇市场询价交易的特点是()。A.交易主体以双边授信为基础 B.
下列关于预防医学的提法中,错误的是A.它以人群为主要研究对象 B.它以环境-人
最新回复
(
0
)