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
52
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
Onemajorobstacletoeconomicdevelopmentispopulationgrowth.Thepopulat
TheUnitedStatesisconsideredamultilingualcountrybutithasneveremp
NationalSpellingBeeEveryyear,thebestyoung【T1】______fromaroundt
某公司施工6间相同的楼面,施工方法一样,均为放钢筋网片,支模板,浇筑混凝土三个过
继电保护和安全自动装置频繁告警属于严重缺陷
下列抗震防灾规划措施中,哪些项是正确的?()A.应尽量选择对抗震有利的地段建
下列哪些是辨证中所说的“毒” A.疫疠之气 B.有毒性作用的特殊病因 C.
罗克奇根据工具—目标维度把价值观分为( )价值观A.工具性 B.终极性 C
贷款风险的预警信号系统中关于经营状况的信号不包括()。 A.丧失一个或多个财
根据增值税一般纳税人即征即退政策的规定,下列说法正确的有( )。A.对提供管道
最新回复
(
0
)