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、Its resin(树脂)isn’t poisonous. B、It can shoot its resin a great distance. C、Its leaves have no veins. D、It doesn’ t need much w
A、Its resin(树脂)isn’t poisonous. B、It can shoot its resin a great distance. C、Its leaves have no veins. D、It doesn’ t need much w
admin
2017-02-24
35
问题
This morning I want to tell you about a recent scientific discovery dealing with the relation between plants and animals. This is about a desert shrub whose leaves can shoot up a stream of poisonous resin a distance of six feet. You think it would be safe from all attacks by insects. But a recent study has found one insect, a beetle, that can chew its way pass the plant’s defense system by cutting the mainly vein that delivers the poison to the leaves. This vein cutting is just one method the beetles used to prepare a safe meal. Another is by cutting a path all the way across the leave to hold the flow of chemicals. Then they simply eat between the veins of poison. In the past, scientists who studied insect adaptation to plant defenses have focused on chemical responses. That is, how the insects can neutral or alter the poisonous substances plants produce. What’s unique about this chewing strategy is that the beetle is actually exhibiting a behavior response to the plant’s defenses rather than the more common chemical response. It is only after a beetle’s survived several encounters with the plant’s resin that it learns how to avoid the poison: by chewing through the resin transporting veins on the next leaf it eats. And thus gives itself a safe meal, however, it can take a beetle an hour and a half of careful vein cutting to prepare a small leaf that takes it only a few minutes to eat ,so, though the method is effective, it’s not very efficient. Now listen to the following recording and answer questions 19 to 21.
19. What is the talk mainly about?
20. What is unusual about the desert plant?
21. Except vein cutting How can the beetles avoid being poisoned by the plant?
选项
A、Its resin(树脂)isn’t poisonous.
B、It can shoot its resin a great distance.
C、Its leaves have no veins.
D、It doesn’ t need much water to grow well.
答案
B
解析
细节题。讲座中提到This is about a desert shrub whose leaves can shoot up a stream of poisonous resin a distance of six feet.即“这是关于沙漠灌木的,它的叶子喷出的有毒树脂流达六英尺之远”。因此,正确答案为B。
转载请注明原文地址:https://kaotiyun.com/show/r1U7777K
0
大学英语六级
相关试题推荐
Since2007,theAmericanPsychologicalAssociation(APA)hasconductedasurveyofdifferentaspectsofstressinAmerica.Thisye
A、Becauseofitsfriendlyfolks.B、Becauseofitscleanair.C、Becauseofitsquietness.D、Becauseofthesenseoffreshness.D关
A、Hethinksthepolice’sactionwasjustified.B、Hethinksthestudentsweretotallywrong.C、Hewantstofindoutthestudents’
A、Hehashadaheartattackbecauseofsmoking.B、Hehasseriouslungdisease.C、Heiscoughingbecauseoftoomuchsmoking.D、H
Adultsaregettingsmarteraboutbowsmartbabiesare.Notlongago,researcherslearnedthat4-day-oldscouldunderstand【B1】__
A、Sheknowsnothingaboutthetenniscourts.B、Shedoesnothaveagoodsenseofdistance.C、Sheisalsoastrangertotheunive
A、Incidentsofworkerscausedglobalanger.B、Kafalasystemleavesworkersopentoabuse.C、AnIndonesianworkerwasstarvedto
A、Water.B、Distance.C、Atmosphere.D、Surfacetemperature.C演讲中提到,“从我们自己的太阳系,我们了解到一颗行星的大气层对于它的气候和供养生命的潜能是至关重要的。”故选C。
随机试题
上海地区某集体机构有风疹流行。有关风疹出疹期的临床特点,下列哪一项应除外
半数致死剂量(LD50)是指
皮肤科门诊中,常常见到女性因使用化妆品不当而导致皮肤病。以下化妆品中最易引起变应性接触性皮炎的是
中国甲公司与澳大利亚乙公司订立了进口羊毛的合同,约定7月1日前阿德雷德港交货,信用证有效期截至7月7日,乙公司7月1日才将货物集港完毕等待装运,因天气恶劣,预计7月5日才能开始装货,乙公司向承运人出具保函,承运人向其出具了7月1日的已装船清洁提单。乙公司顺
企业人力资源短期规划是指时间为()的规划。
社会基本矛盾的运动总是从()的变化开始。
A、 B、 C、 D、 C此题答案为C。观察两组图形,每组图形的内部图形与外部图形相接的边数,依次是0、1、2。当然,只有这一个规律并不能直接选出答案,因此,还需寻找别的规律。从另一个角度考虑,第一组图形中,
在城镇化过程当中,当城镇化率超过50%以后,城镇化减速的现象将逐渐出现。阻止城镇化减速的一个必备的战略思路是加快农民工市民化进程,加快这一进程的一个必要举措是建设农民工信息系统和信用体系。由此可以推出()。
设函数u(x,y)=φ(x+y)+φ(x一y)+∫x一yx一yψ(t)dt,其中函数φ具有二阶导数,ψ具有一阶导数,则必有
KatharineGrahamgraduatedfromtheUniversityofChicagoin1938andgotajobasanews【B1】______inSanFrancisco.Katharine
最新回复
(
0
)