首页
登录
职称英语
WATER AND LIFE ON MARS1 The presence or absence of water
WATER AND LIFE ON MARS1 The presence or absence of water
游客
2024-01-04
51
管理
问题
WATER AND LIFE ON MARS
1 The presence or absence of water has a direct bearing on the possibility of life on other planets. In the nineteenth century, it was commonly accepted that life, perhaps even intelligent life, was widespread in the solar system, and Mars was an obvious target in the search for life. New photographic technology offered a way for astronomers to learn more about the red planet. In 1888, Italian astronomer Giovanni Schiaparelli produced images that showed a network of long, thin, dark lines crossing the surface of Mars. He called these features canali in Italian, which became "canals" or "channels" in English. The strange appearance of the canals suggested to some scientists that they had been formed artificially rather than naturally. The mystery deepened when Schiaparelli observed that many of the canals in the photographs were actually double.
2 Other photographic images of Mars revealed its seasonally changing polar ice caps and features that appeared to be ancient islands located in what was now a dry streambed. When the islands were first discovered, some scientists speculated that a thick water-laden atmosphere capable of generating heavy rains had once existed on Mars. However, others remained unconvinced of the presence of water. Then, in 1963, a team of astronomers obtained a good photographic plate of the near-infrared spectrum of Mars. The photograph showed that, faintly but definitely, water vapor lines could be seen. This photograph established that there really was water on Mars, though the amount was very small.
Today, the presence of water vapor in the Martian atmosphere is generally accepted, as is the belief that the atmosphere was once much denser than it is now, with a much greater abundance of water vapor.
3 The surface of Mars is dry today, but it does contain significant amounts of ice and signs that liquid water once flowed over the planet. All of the locations where evidence of water has been found are ancient, probably formed very early in Martian history. Data transmitted from spacecraft on Mars in 2004 have revealed that water was once common across a vast region of the planet, possibly as shallow lakes or seas that dried out and then filled up again. There are signs that the wind blew debris around during dry stages. These seas and lakes extended across hundreds of thousands of square miles, creating
habitable
conditions during long stretches of time billions of years ago.
4 Evidence of water includes the presence of various minerals known as evaporates, deposits left behind when liquid water turns to vapor. Small areas of mineral deposits have been found in Valles Marineris, a huge hole on Mars that is larger than the Grand Canyon on Earth. The minerals there contain water, so they had to be formed in the presence of water. Geologic research has also turned up clay and gypsum deposits that were formed by water in the soil. Rocks that clearly formed in water extend throughout 300 meters of layered materials in several locations across the Martian plains. The layers were built up over time, which means water was present, at least temporarily, for extended periods on ancient Mars.
5 Besides the ice packs at Mars’s poles, astronomers have discovered a frozen sea near its equator. This frozen sea is the size of the North Sea on Earth and appears similar to the ice packs on Antarctica. Scientists have also detected evidence of lava flows 20 million years ago as well as signs that some volcanoes may still be active. Several recently formed volcanic cones near Mars’s North Pole indicate that the planet’s core may interact with the surface, meaning there was both warmth and moisture in the recent pas-circumstances that might have supported life.
6 Liquid water is the key ingredient for life as we know it. Of all the other planets in the solar system, Mars is most like Earth. The fact that water existed on ancient Mars does not necessarily mean life ever emerged there; however, all of the available evidence does suggest that Mars meets all the requirements that are needed for life to exist. [br] Look at the four squares,A ,B, C, and D, which indicate where the following sentence could be added to the passage. Where would the sentence best fit?
Astronomers already knew that Mars had some kind of atmosphere because of the occasional presence of bright features that looked like clouds.
The presence or absence of water has a direct bearing on the possibility of life on other planets. A In the nineteenth century, it was commonly accepted that life, perhaps even intelligent life, was widespread in the solar system, and Mars was an obvious target in the search for life.B New photographic technology offered a way for astronomers to learn more about the red planet. In 1888, Italian astronomer Giovanni Schiaparelli produced images that showed a network of long, thin, dark lines crossing the surface of Mars.C He called these features canali in Italian, which became "canals" or "channels" in English. The strange appearance of the canals suggested to some scientists that they had been formed artificially rather than naturally.D The mystery deepened when Schiaparelli observed that many of the canals in the photographs were actually double.
选项
A、Square A.
B、Square B.
C、Square C.
D、Square D.
答案
B
解析
In the added sentence, Astronomers already knew that Mars had some kind of atmosphere logically follows Mars was an obvious target in the search for life in the previous sentence. (1.8)
转载请注明原文地址:https://tihaiku.com/zcyy/3332648.html
相关试题推荐
"ExcusedAbsence"Readashortpassageandlistentoatalkonthesamet
WATERANDLIFEONMARS1Thepresenceorabsenceofwater
WATERANDLIFEONMARS1Thepresenceorabsenceofwater
WATERANDLIFEONMARS1Thepresenceorabsenceofwater
WATERANDLIFEONMARS1Thepresenceorabsenceofwater
WATERANDLIFEONMARS1Thepresenceorabsenceofwater
WATERANDLIFEONMARS1Thepresenceorabsenceofwater
WATERANDLIFEONMARS1Thepresenceorabsenceofwater
IndividualPerformanceandthePresenceofOthersP1:Aperson’sperformanceon
IndividualPerformanceandthePresenceofOthersP1:Aperson’sperformanceon
随机试题
Childrenwhosemindswandermighthavesharperbrains,researchsuggests.A
ThediagrambelowillustratestheinformationprovidedinparagraphsB-FofRe
图示平面体系的计算自由度为: A.0个 B.2个 C.1个
DHCP客户端可从DHCP服务器获得()A.DHCP服务器的地址和Web服务器的
2021年1月1日起,以下法律终将被废止的有()。A、《中华人民共和国婚
某公司2015年度归属于普通股股东的净利润为15000万元,发行在外的普通股加权
根据《非上市公众公司监督管理办法》,在公众公司收购中,收购人持有的被收购公司的股
在我国,机构投资者主要包括()。 Ⅰ、私募基金公司 Ⅱ、保险公司 Ⅲ、公
下列各项,用纤维结肠镜检查对诊断最有意义的是()A.神经官能性腹泻 B.
经济萧条时期宏观经济的表现有(). A.从业率增大B.出现大量企业倒闭
最新回复
(
0
)