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
Bees that help with pollination benefit flowers and【L31】________. Bees produce wax that can be made into candles and【L32】_______
Bees that help with pollination benefit flowers and【L31】________. Bees produce wax that can be made into candles and【L32】_______
admin
2022-09-09
25
问题
Bees that help with pollination benefit flowers and【L31】________.
Bees produce wax that can be made into candles and【L32】________.
Dragonflies primarily eat【L33】________.
Insects in summer can be harmful because they can carry such deadly diseases as malaria,
yellow fever, and【L34】________.
Harmful insects may destroy crops, clothes, furniture, and even the【L35】________.
【L31】
Good afternoon, and welcome to Insect Biology 101. I’d like to begin this course with a few remarks about good insects and bad ones. Bugs are all around us and that’s both a benefit and an annoyance — sometimes maybe even serious harm. First, let’s talk about the good things that insects do for us.
Probably the most important insect for humans, and maybe for all other life, is the bee. Bees help plants in the process of pollination, and
thus are necessary to most flowers and fruit trees
. That is, they carry pollen from ‘male’ flowers to ‘female’. If it weren’t for bees, we’d have very few food plants and no fruit either. In fact, there would be no ‘we’. No less a thinker than Albert Einstein pointed out that, without bees, humanity would be dead within a year or less. We’d starve. It’s that simple. That should maybe make us just a little humble.
A little less dramatic is the fact that bees also make the honey we eat. Moreover,
they produce beeswax, which is useful in candles and it’s also used as a first-rate furniture polish
. Sure, these may not be vital to our lives, but they can serve as reminders of how important bees are. That’s a point I keep coming back to in this course. Though, in all fairness, I should point out that butterflies aid in pollination as well as bees.
Now, here in Michigan, what’s the worst part of summer? Yep, that’s right — mosquitoes. But I’m talking about helpful insects, right? So let’s look at the dragonfly first. If there were no dragonflies, there would be even more mosquitoes!
Dragonflies mainly eat mosquitoes and also a few other insects
. Yes, that’s right. They don’t just fly around, and they also help to eliminate harmful insects. So, the next time you see a dragonfly, don’t you dare kill it!
Now let’s talk a little about those harmful insects. Take the mosquitoes I just mentioned as an example. Not so many years ago, mosquitoes here in America weren’t just annoying. Some were even deadly. They carried malaria and yellow fever. My own ancestor, the Confederate General John Bell Hood, lived through the worst battles of Civil War only to die at age thirty-eight from yellow fever. A pest, not a bullet!
Well, besides the mosquitoes, in summer there is also a kind of insect that never seems tired. Right, that is the fly. Before I go on talking, I must mention an African fly called the Tsetse fly, which feeds on blood and can cause serious diseases in the people and animals that it bites.
Besides, it is still a bearer of sleeping sickness
, which affects around 300,000 people every year in Africa and can be treated only with toxic drugs that are hard to administer. Worse still, the drugs sometimes don’t work.
Other insects, of course, destroy food crops. In China, for instance, locusts continue to be a danger to the harvest in some areas. Less important, but still annoying, moths eat people’s clothes and dust mites slowly destroy carpets. Worse, but still in the home, termites or "white ants" eat wood — the wood of your house.
If they are not stopped, they can eventually destroy the whole building
. Usually, they seriously damage a building before anyone even notices them. So, as we all know, insects can be a real trouble.
For some decades in the West, to kill insects with chemicals seemed a good remedy. Unfortunately,
chemicals can only be used in a limited area for a limited time. It’s a small-scale solution
. The insects come back. Worse still, some of the poisons used like DDT were found harmful to the environment. Many kinds of wildlife, like hawks, were harmed. And people in chemical-using rural areas have one of the highest rates of liver cancer in the world.
It’s no secret that the chemicals remain harmful to humans
.
Like all species, insects adapt to their changing environments at an amazing rate. When a new chemical is introduced to their habitat, the insects that survive are generally the ones with some way of resisting the harmful effects. They then breed with the other survivors, and
just like that insects become resistant to most poison in a few generations
. An insect generation, remember, is a couple of months at most!
So, again we have to ask: what to do? Well, there are biological solutions. Some of these are pretty simple. One is destroying the insects’ habitat. You take away their home or food. Cleaning your kitchen is the best way to prevent roaches. No garbage: no food. Getting rid of marshes and swamps eliminates mosquitoes. Other solutions might include bringing in dragonflies or bats in areas where mosquitoes are many.
This is a cheaper alternative to chemicals
. Biological methods like this also bring no extra pollution to the environment. But you have to be careful. If you change the environment too much, you might be hurting other forms of life accidentally.
One recent method of controlling insect populations involves interrupting their breeding cycle. What does that mean? It means ‘birth control for bugs’. Insects are provided with food that makes them unable to reproduce. Since they can’t have babies, the population disappears, or nearly so. And since no young are born, resistance is not a problem with no young insects developing increased resistance.
Interrupt the life cycle, eliminate the bug!
It’s clear that we must have an understanding of the life cycle of the insect
. At least, that’s the plan. We’ll go into more details as this course goes along. Now I will stop here to see whether you have any questions or not.
选项
答案
fruit trees
解析
空格前为and,推测应填入和flowers并列的名词。录音原文中的help…pollination是的原词复现,录音中的are necessary to是benefit的替换表达,故空格处应填入fruit Wees。
转载请注明原文地址:https://kaotiyun.com/show/fQnD777K
本试题收录于:
雅思听力题库雅思(IELTS)分类
0
雅思听力
雅思(IELTS)
相关试题推荐
以下叙述中错误的是()。
以下关于循环语句的叙述中正确的是()。
考生文件夹下有一个数据库文件"samp2.mdb",其中存在已经设计好的表对象"tStud"和"tTemp"。tStud表是学校历年来招收的学生名单,每名学生均有身份证号。对于现在正在读书的"在校学生",均有家长身份证号,对于已经毕业的学生,家长身份证号为
Morethantwo-thirdsofadultsintheUnitedStatesareoverweightandhalfofthemaretryingtoloseweight.Accordingtoare
Whatisthetutor’sopinionofthefollowingcompanyprojects?Tutor’sopinionAItwouldbeveryrewardingforthestudent.
ResearchingtheoriginofmedievalmanuscriptsBackgroundMedievalmanuscripts—handwrittenbooksproducedbetweenthefift
TheGherkinBuildingCommissionedby:【L31】________firmcalledFosterandPartnersThefeaturesofitsappearance:Itsshapeis
TheGherkinBuildingCommissionedby:【L31】________firmcalledFosterandPartnersThefeaturesofitsappearance:Itsshapeis
CharacteristicsofAmericanCultureI.PunctualityA.Goingtothetheaterbe【T1】______twentyminutesprior
Arapidmeansoflong-distancetransportationbecameanecessityfortheUnitedStatesassettlementspreadfartherwestward.F
随机试题
StudiesShowU.S.SpendingDoesn’tGetBestHealthTheUnitedStatesmayspendtwiceasmuchonhealthcareasotherrich
A.阴道分泌物悬滴检查B.子宫输卵管碘油造影C.宫颈刮片检查D.官颈黏液检查E.B型超声检查检查有无白假丝酵母菌感染的为
A.猪繁殖与呼吸综合征病毒B.猪瘟病毒C.日本脑炎病毒D.猪水疱病病毒E.猪圆环病毒2型3月龄猪,体温41℃,全身皮肤有出血点,死亡迅速。剖检见喉头有出血点,扁桃体有坏死灶,脾脏边缘有出血性梗死灶,肾脏见大小不一的出血点。该病最可能的病原是
A.养胃舒胶囊B.参芪降糖胶囊C.八珍颗粒D.生脉饮E.大补阴丸治疗气血两虚所致的面色萎黄,食欲不振,四肢乏力,首选
计算下列各项指标时,其分母需要采用平均数的有()。
某公司某年全年利润总额是2000万元,所得税税率为25%;需要用税后利润弥补的亏损额是50万元;公司按规定提取法定公积金后,不再提取任意盈余公积;第二年的投资计划拟需资金1200万元。此投资计划的目标资金结构为自有资金为60%,借入资金为40%。另外,
《中小学幼儿国家安全管理办法》规定,小学、幼儿园应该建立中低年级学生、幼儿上下学时接送的交接制度,不得将晚离学校的中低年级学生、幼儿交与无关人员。()
PMCTWYNAQCMENL
请用不超过150字的篇幅,概括出给定资料所反映的主要问题。以政府调研员的身份,用不超过350字的篇幅,提出解决给定材料所反映问题的方案。要有条理地说明,要体现针对性和可操作性。
[*]
最新回复
(
0
)