首页
登录
职称英语
Isn’t it surprising that scientists have a better understanding of how many
Isn’t it surprising that scientists have a better understanding of how many
游客
2023-09-25
9
管理
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. [br] 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://www.tihaiku.com/zcyy/3043420.html
相关试题推荐
Accordingtomanyscientists,solarenergywillbeused______(extend)inthe2
Accordingtomanyscientists,solarenergywillbeused______(extend)inthe21
Whatsurprisingitemscancamelschewup?Camelscanchewupsharp______.[or
Iliketolistentotheradiomuchbetterthan(watch)______television.towatc
Whyarescientistssurprisedbythefindingsintheirnoisestudy?[br]Whichof
Whyarescientistssurprisedbythefindingsintheirnoisestudy?[br]Fromthe
Whyarescientistssurprisedbythefindingsintheirnoisestudy?[br]Whenthe
(take)______thefinancialdifficultiesintoconsideration,we’dbetterputoff
WhendidscientistscometorealizehowtheatomsandmoleculesontheEarthmos
WhendidscientistscometorealizehowtheatomsandmoleculesontheEarthmos
随机试题
Thepassagegivesabriefdescriptionofthecontentofanewbook,AHistoryof
A.四逆散 B.半夏泻心汤 C.茵陈蒿汤 D.青蒿鳖甲汤 E.蒿芩清胆汤
医用直热式热敏相机的功能是A.把数字影像通过发热电极转换成灰阶影像 B.把数字
如图a)所示结构,若将链杆撤去,取图b)为力法基本体系,则力法方程及知分别为:
债券交易双方约定在未来某一时刻按照现在确定的价格进行交易的债券交易种类是(
下列哪项不属于滑脉所主病证?( )A.痰饮 B.食滞 C.实热 D.疟疾
对急性脑出血的患者护理措施不正确的是A.偏瘫患者穿衣时先穿健侧,再穿患侧 B.
大黄类饮片中,以消积化瘀为主的是A.醋大黄B.酒大黄C.熟大黄D.大黄炭E.清宁
下列关于人员疏散安全性评估的说法,错误的是()。A.火灾中人员的安全疏散指的是
根据国家发改委《必须招标的工程项目规定》和《必须招标的基础设施设施和公用事业项目
最新回复
(
0
)