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
Where does the plant grow?
Where does the plant grow?
admin
2009-03-16
28
问题
Where does the plant grow?
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 rosin for a distance of six feet. Do you think it would be safe from all attacks by insects? But a recant study has found one insect, a beetle, which can chew its way past the plant’s defense system by cutting the main vein that delivers the poison to the leaves. This vein cutting is jut one method the beetles used to prepare a safe meal. 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. It is only after a beetle has 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 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.
选项
答案
chemical responses
解析
转载请注明原文地址:https://kaotiyun.com/show/sJPd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
Note:AnswereachquestionbychoosingA,B,CorDandmarkitonANSWERSHEET1.Somechoicesmayberequiredmorethanonce.
Note:AnswereachquestionbychoosingA,B,CorDandmarkitonANSWERSHEET1.Somechoicesmayberequiredmorethanonce.
Note:AnswereachquestionbychoosingA,B,CorDandmarkitonANSWERSHEET1.Somechoicesmayberequiredmorethanonce.
AccordingtotheAmericanAcademyofDermatology,anestimated10to50millionpeopleinthiscountryhaveanallergicreaction
Whatdoesthespeakersuggestthatthestudentsshoulddoduringtheterm?
What’stheaverageincreaseperyearofforeignstudentpopulationintheperiodbetween1985and1990intermsofpercentage?
What’stheaverageincreaseperyearofforeignstudentpopulationintheperiodbetween1985and1990intermsofpercentage?
Whatdoesthelecturemainlyconcern?
What’stheaverageincreaseperyearofforeignstudentpopulationintheperiodbetween1985and1990intermsofpercentage?
随机试题
实心圆轴受扭,若将轴的直径减小一半时,则圆轴的扭转是原来的16倍。()
A.假肿瘤阴影B.鹰嘴样阴影C.杯口状阴影D.膈下新月形阴影E.阶梯状气液平面小肠扭转的X线表现为
无论采取市场方式还是采取非市场方式组建企业集团,都应当坚持符合国家产业政策和经济发展战略要求的原则,坚持政企分开、出资人自愿组合的原则,坚持反对行业垄断、地区封锁,鼓励跨地区、( )组建的原则。
关于立井吊桶提升时安全要求的说法,正确的有()。
质量管理体系认证的意义在于()。
下列选项中,不属于版权特征的是()。
下列财产作为抵押物时,()应当办理抵押登记,抵押权自登记时设立。
统计图根据下图提供的信息回答116~120题。从图中可看出,该企业收入大于50万的月份有几个月?()
简述鲁利亚脑机能系统学说。
中华传统美德源远流长,内容丰富。下列表述中,集中体现追求精神境界,向往理想人格的传统美德的有
最新回复
(
0
)