ITisalwayshardforasmallfishtoliveinabigpond.Pluto’srece...
问题详情:
IT is always hard for a small fish to live in a big pond. Pluto’s recent departure(离开) from the classical planet family clearly proves that size really matters.
Astronomers voted on August 24 to create the first scientific definition of the word “planet”, and Pluto obviously didn’t make the cut. It turned out to be only a “dwarf planet”(矮行星).
After weeks of heated debate, over 2,500 astronomers from 75 countries voted on the definition of a “planet” at a conference of the International Astronomical Union (IAU). According to the definition, a planet must have a clear neighborhood around its orbit(轨道). Pluto has widely been considered a planet since its discovery in 1930. Unfortunately, it has a special orbit which overlaps with Neptune’s. It is all because, compared with Neptune, Pluto is very small. It is attracted by Neptune’s gravity when the two planets get closer.
According to IAU. a “dwarf planet” should have an orbit around the sun. It will not have a clear neighborhood around its orbit, and must not be a satellite. The new classification means that the science textbooks will have to be updated. The solar system is now made up of the eight “classical planets,” together with a number of dwarf planet. The classical planets are: Mercury; Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The debate over Plates status started in 1992. After an advanced telescope was sent into space, astronomers started to find a belt of objects, which lies beyond Neptune. The belt contains nearly 1,000 objects, including Pluto. As they continued the exploration, scientists recently discovered at least 41 dwarf planets at the edges of the solar system. There are at least two objects of a similar size to Pluto.
It seems that even if the IAU had kept Pluto’s status as a planet, the classical theory of nine planets in the solar system would have had to be changed, but the other way around. More dwarf planets of a similar size to Pluto would join the family of planets. Scientists will probably find many more dwarf planets.
1.According to the passage, Pluto is ___________.
A.a planet which has a clear neighborhood around its orbit
B.a satellite of Neptune which was discovered in 1930
C.is the smallest planet in the solar system
D.a planet which has an orbit around the sun
2.The sentence “IT is always hard for a small fish to live in a big pond” quoted in the beginning of the passage is used to _______________.
A.tell us small fish can hardly survive in the big pond
B.tell us the size of an object really matters
C.mean that small planet can hardly exist in the solar system
D.explain the disappearance of Pluto in the solar system
3.From the last paragraph we can infer that if IAU kept Pluto’s status as a planet, the number of planets in the solar system would be ________________.
A.eight B.nine C.less than nine D.more than nine
4.Which of the following statements is NOT true according to the passage?
A.According to definition of a “planet”, if Pluto were bigger it would not have left the classic planet family.
B.More dwarf planets of a similar size to Pluto would join the family of planets. Many more dwarf planet will be found by the scientists in the future.
C.Pluto has a special orbit which overlaps with Neptune’s because it is so small as to be attracted by Neptune’s gravity when the two planets get closer.
D.A “dwarf planet”, which must not be a satellite without a clear neighborhood around its
orbit, should have an orbit around the Sun.
【回答】
DBDA
知识点:阅读理解
题型:未分类
-
反比例函数与直线相交于点点的横坐标为,则此反比例函数的解析式为( ) A. ...
问题详情:反比例函数与直线相交于点点的横坐标为,则此反比例函数的解析式为( ) A. B. C. D.【回答】C;知识点:反比例函数题型:选择题...
-
某班抽取6名同学进行体育达标测试,成绩如下:80,90,75,80,75,80.下列关于对这组数据的描述错误的...
问题详情:某班抽取6名同学进行体育达标测试,成绩如下:80,90,75,80,75,80.下列关于对这组数据的描述错误的是( )A.众数是80 B.平均数是80 C.中位数是75 D.极差是15【回答】C知识点:数据的集中趋势题型:未分类...
-
对课文的分析有误的两项是( )(2分)A.《日出》作者选取了一个十分独特的角度——描绘作者从国外出访...
问题详情:对课文的分析有误的两项是( )(2分)A.《日出》作者选取了一个十分独特的角度——描绘作者从国外出访归来,在海中轮船上目睹的一次“最雄伟,最瑰丽的日出景象”。B.《泰山日出》是用诗化的语言写成的,韵律*,比喻新奇,想象丰富,意境优美。C.《日历》这篇...
-
默写古诗名句,并写出相应的作家、篇名。(12分)①像野马在平原上奔驰,像 ,...
问题详情:默写古诗名句,并写出相应的作家、篇名。(12分)①像野马在平原上奔驰,像 ,像 。②五岭逶迤腾细浪, 。(*《七律·长征》)...
相关文章
- Ifoverweightpeopleeatlessandtakemoreexercise,they’llso...
- Iliveinabigcitywithalotofhomelesspeople.Luckilythere’re...
- —I’veshownyoualltheinterestingandimportantplacesofours...
- Iliveinabigcitywithalotofhomelesspeople.Luckily,there'r...
- Equippedwithmodernfacilities,today’slibrariesdiffergrea...
- Itisalwayshardforasmallfishtoliveinabigpond.Pluto'srece...
- Lifeiscolorful.Sometimesit’sjustlikepotatosalad;whenit'...
- “IgrewuponJackson’smusicandIstillhaveallhisstuffonMyiP...
- Withalltheresponsibilities(责任)wefaceinourdailylives,it’...
- Theworld’sfirst“SkyPool”hasbeenuncoated(曝光)--andit’llgi...