首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Isn’t it surprising that scientists have a better understanding of how many stars there are in the galaxy (银河系) than how many sp
Isn’t it surprising that scientists have a better understanding of how many stars there are in the galaxy (银河系) than how many sp
admin
2013-02-05
99
问题
Isn’t it surprising that scientists have a better understanding of how many stars there are in the galaxy (银河系) than how many species there are on Earth? Their estimates of global species diversity vary from 2 to 100 million species. Most people agree on an estimate of somewhere near l0 million and yet only 1.75 million have actually been named. Current knowledge of species diversity is limited. This problem becomes more serious because there is a lack of a central database or list of the world’s species.
New species are still being discovered — even new birds and mammals(哺乳动物). On average, about three new species of birds are found each year, and since 1990, 10 new species of monkeys have been discovered. Other groups are still far from being completely described: an estimated 40 percent of freshwater fishes in South America have not yet been classified.
Scientists were started in 1980 by the discovery of a huge diversity of insects in tropical forests. In one study of just 19 trees in Panama, 950 new species of beetles were discovered.
As scientists begin investigating other little-known ecosystem, like the soil and the deep sea, "surprising" discoveries of species become commonplace. There is nothing strange about this, though, since as many as a million undescribed species are believed to live in the deep sea. And one gram of a small-sized piece of land might hold 90 million bacteria(菌类) and other microbes (微生物). How many species these communities contain is still anyone’s guess.
Which of the following best reveals the main idea of the passage?
选项
A、Surprising discoveries of new species are commonplace.
B、The mystery of the deep sea and the soil remains to be uncovered.
C、Knowledge of global species diversity is still limited.
D、Estimates of global species diversity vary among scientists.
答案
C
解析
主旨大意题。通读全文可以发现,作者一直在介绍地球物种的局限性。因此C选项最符合题意,故选C。
转载请注明原文地址:https://kaotiyun.com/show/B4lK777K
本试题收录于:
大学英语三级A级题库大学英语三级分类
0
大学英语三级A级
大学英语三级
相关试题推荐
A、Toaconcert.B、Toherbrother’shouse.C、Tohisprofessor’soffice.D、Toabirthdayparty.D
Whatistheletterabout?It’saboutproblemswithsalesof______inPakistan.Whatisthefirstproblem?______.
Inbusiness,manyplacesadoptacreditsystem,whichdatesbacktoancienttimes.Atpresent,purchasescanbemadebyusingcr
A、Becausehewaslate.B、Becausehedidn’tpasstheEnglishtest.C、Becausehedidn’tpassthemathtest.D、Becausehismathtea
YouarerequiredtowritealetterofintroductionaccordingtothefollowinginformationgiveninChinese.你的朋友的儿子杨明想去美国深造,
Itissaidtheconferenceis______(hold)inthishallnextmonth.
Whydopeopledecidetouseamachinetranslationprograminsteadofusingahumantranslator?Becauseitis___________________
Whydopeopledecidetouseamachinetranslationprograminsteadofusingahumantranslator?Becauseitis___________________
A、Shehasnoboyfriend.B、Sheisgoingbacktoherhometown.C、Sheisgoingtovisitherboyfriend’sparents.D、Sheisveryner
Mysuggestion______weshouldsticktoouroriginalplanwasfinallyaccepted.
随机试题
关于律师担任政府法律顾问,以下说法不正确的是哪个选项?()
提高运输工具的使用效率的途径包括哪些?
Threepassions,simplebut【C1】______(overwhelm)strong,havegovernedmylife:thelongingforlove,thesearchforknowledge,a
A.尾蚴B.胞蚴C.囊蚴D.包囊E.卵囊日本分体吸虫的感染阶段是
在碳水化合物中致龋性最强的是
有关维生素B12所致的巨幼红细胞性贫血的描述,错误的是
用高效液相色谱法测定靛玉红的中药材是()。
以地上无定着物的出让土地使用权抵押的,由房地产管理部门办理抵押登记。()
根据我国宪法和法律,城市土地属于()。
Smilinganddapper,FazleHasanAbedhardlyseemslikearevolutionary.ABangladeshieducatedinBritain,anadmirerofShakesp
最新回复
(
0
)