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
A、Some of them are living in the wild in Hawaii. B、None of them live in the wild. C、They are the most valuable species of crows.
A、Some of them are living in the wild in Hawaii. B、None of them live in the wild. C、They are the most valuable species of crows.
admin
2021-07-23
94
问题
Hello, everybody. Today, I am going to talk about birds using tools.
Scientists have long known that a crow native to New Caledonia is able to use tools. The birds use them to remove food from deep inside holes and crevices. Now, American researchers have discovered a second species of crow that uses tools. Researchers with the San Diego Zoo reported on their experiments with Alala crows—a species from the Hawaiian Islands. There are no more Alala crows living in the wild. But there are some of the birds still living in a protected area in Hawaii. They are considered critically endangered. In an experiment, the researchers placed pieces of food in crevices inside a big piece of wood. The holes are too deep for the birds to reach with their beaks. But, by using small pieces of wood held in their beaks, the birds quickly found a way to get the food. The scientists said the crows demonstrated the ability to reach food in those cannot-reach-it places. The birds used small objects as tools, sometimes changing them by shortening a too-long stick. They also made tools from plant material. "Current evidence strongly suggests that tool use is part of the species’ natural behavioural pattern" , Rutz said.
Alalas are not the only intelligent crows to use tools. The other is the New Caledonian crow on New Caledonia Island in the Pacific Ocean. The New Caledonian crow can use tools to remove insects and other food from dead wood and plants.
How did crows learn to use tools? How did these birds learn to use tools? Scientists think their tool-using skills may have resulted, in part, from conditions in their Pacific island habitat. The two species have one more thing in common: unusually straight beaks. The birds use their beaks like the way people use thumbs on their hands.
All the Alala crows left in the world live in Hawaii. There were less than 20 Alalas left in the late 1990s when scientists decided to bring them into a protected area to increase their population. Now, there are over 100 birds living in captivity. The San Diego Zoo said its researchers tested almost all of them and "they determined that the vast majority of them spontaneously used tools. " Scientists are working to increase the population so that the Alala can be released back into the wild. They plan to release some of the birds back into the wild later this year.
Questions 23 to 25 are based on the recording you have just heard.
23. What does the speaker say about Alala crows?
24. What does Rutz say about the tool use of Alala crows?
25. What can we learn about the two species of crows?
选项
A、Some of them are living in the wild in Hawaii.
B、None of them live in the wild.
C、They are the most valuable species of crows.
D、They live in deep holes on the rock.
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/gSJ7777K
0
大学英语六级
相关试题推荐
Forthispart,youareallowed30minutestowriteashortessayentitledHowtoCopewithGraduationStress?Youshouldwritea
Forthispart,youareallowed30minutestowriteashortessaytoexplainWhyarePeoplenotWittingtoHelp.Youressayshoul
Forthispart,youareallowed30minutestowriteashortessayentitledOnUniversityStudents’TakingPartinVoluntaryTeach
Forthispart,youareallowed30minutestowriteashortessayentitledOnTeacherAppraisalSystem.Youshouldwriteatleast
A、Laughingisalearnedbehavior.B、Laughingisagoodmedicinetopatients.C、Laughingiseasierthanbattlingwithanillness.
A、Becausemanystudentsarecheatinginexam.B、Becausetheyhavetheaccesstosmartphones.C、Becausethepressurefromtheir
Secondhandsmokeisaccountablefor42,000deathsannuallytononsmokersintheUnitedStates,includingnearly900infants,acc
DoBritain’sEnergyFirmsServethePublicInterest?[A]Capitalismisthebestandworstofsystems.Lefttoitself,itwillemb
Theincreaseinglobaltrademeansthatinternationalcompaniescannotaffordtomakecostlyadvertisingmistakesiftheywantt
A、Theyarepoweredbybattery.B、Theydon’tdelivernicotine.C、Theydon’tlooklikecigarettes.D、Theywillsoonbeonthemark
随机试题
拥有少量受过高等教育人口的国家注定在经济和政治上疲软。然而,拥有大量受过高等教育人口的国家,他们的政府对公共教育有严肃认真的财政承诺。所以,任何一个拥有能做出这种承诺的政府的国家,都会摆脱经济和政治的疲软。以下哪项论证中的缺陷与上述论证中的最相似?
()是贷前调查中最常用、最重要的一种方法。(2010年上半年)
发展就是变化,不仅包括新事物的产生旧事物的灭亡,也包括事物数量的增长和场所的变更。()
群众赵某的车被限速指示牌砸了,在理赔过程中,保险公司要求赵某提供指示牌产权单位开出的证明,赵某向相关政府部门打了50多个电话都没有问到该指示牌“归谁管”。对此请谈谈你的看法。
下列属于被试间设计的是()
试述七千人大会前后开展的政治关系调整方面的情况。
下列是一台Cisco路由器的部分路由表信息,表中的路由信息完全正确的是()。
Thedeanmadeaproposalthatallstudents(make)______asocialinvestigationonSummerVacation.
Thecommanderorderedthatwe(withdraw)______assoonaspossible.
PleaseObserveTrafficRules1.据统计,13%住院治疗的人是因为车祸2.举例说明不少司机、行人、骑车的人不遵守交通规则3.呼吁为了自身和他人的安全,请自觉遵守交通规则
最新回复
(
0
)