首页
登录
职称英语
[originaltext] Cultural controls are the oldest methods that have been used
[originaltext] Cultural controls are the oldest methods that have been used
游客
2023-08-27
72
管理
问题
Cultural controls are the oldest methods that have been used to manage pest populations. However, with the development of synthetic pesticides these controls were rapidly abandoned or de-emphasized and research on them was largely discontinued.(29)Today, we are going to talk about a natural way some plants respond to being invaded by pests. The plants react by emitting a chemical signal, which acts like a call for help. Let’s take corn plants for example. Sometimes,(30)a kind of insects that cannot fly chew on the com leaves; when this damage happens, the plant releases a chemical scream that attracts a kind of bees. The bees respond to the signal by flying to the chewed on leave, and laying their eggs on the insects.(31)The insects die in the next few days as the bees’ offspring will eat the insects. Thus the corn plant prevents all its leaves from being eaten by the insects. This chemical scream is specific. It’s only released after the plant has damaged by the insects. A plant damaged in other ways does not give off the same signal, nor does undamaged plants. Cotton and probably many other plants use similar type of defense against pests.(32)By enhancing this natural response in plants, researchers might reduce, some day even eliminate the need for chemical pesticide, which can cause ecological damage. For example, scientists might breed plants for this screaming trait, or they might transplant specific genes to increase the release of the chemical signals.
29. What’s the main purpose of the talk?
30. What causes the corn plant to emit the chemical signal?
31. How do the bees protect the damaged corn plant?
32. What is the meaning of enhancing this natural response in plants?
选项
A、To describe ways pests can damage plants.
B、To examine the life cycle of corn plants.
C、To explain how corn plants develop.
D、To describe how a natural pesticide works.
答案
D
解析
文章在开头部分提到,本文要讲的是一些植物直接对抗入侵昆虫的自然方法,故答案为D)。
转载请注明原文地址:https://tihaiku.com/zcyy/2961666.html
相关试题推荐
[originaltext]JaimeEscalantewasconsideredoneofthebestteachersinth
[originaltext]JaimeEscalantewasconsideredoneofthebestteachersinth
[originaltext]JaimeEscalantewasconsideredoneofthebestteachersinth
[originaltext]ItseemstomethatneighborsaregoingoutofstyleinAmeri
[originaltext]ItseemstomethatneighborsaregoingoutofstyleinAmeri
[originaltext]Theestimatedone-fifthofchildreninLondon’sschoolswhoc
[originaltext]W:Withusnow,isMalcolmBricklin,CEOofVisionaryVehicles.M
[originaltext]W:Withusnow,isMalcolmBricklin,CEOofVisionaryVehicles.M
[originaltext]M:It’sniceandquiethere,awayfromthedustandnoiseofthe
[originaltext]M:It’sniceandquiethere,awayfromthedustandnoiseofthe
随机试题
Titled:TheNewRevelationsofNetEconomyTimelimit:40minutesWo
[originaltext]W:Everybodyshoulddohisbitforthedinnerparty.Wouldyouma
WhichofthefollowingitalicizedpartsexpressesPURPOSE?A、Itisrighttogive
燃煤锅炉房位置选择下列哪项不合适?()A.热负荷集中 B.重要建筑物下风侧
双面水准尺多用于三、四等水准测量,其长度有2m和3m两种,且两根为一对。
当桥梁出现()情况时,应进行特殊检查。A.桥梁技术状况为4类 B.超重车辆通
流行性出血热为A.肠道传染病 B.自然疫源性疾病 C.性传播疾病 D.烈性
患者男,40岁,严重肝病导致营养不良,实验室检测其补体总活性CH50,其通常会(
“能辨别自己的左右”,这一数学认知目标适合的年龄班是()A.小班 B.中班
国家统计局的主要职责包括()。 A.拟订统计工作法规、统计改革和统计现代化建
最新回复
(
0
)