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、It can cause flooding B、It can carry diseases that affect animals. C、It can introduce too much salt into the soil. D、It can di
A、It can cause flooding B、It can carry diseases that affect animals. C、It can introduce too much salt into the soil. D、It can di
admin
2018-11-19
17
问题
Today, I’d like to talk about some of the changes land can undergo, specifically desertification, that’s the process through which land becomes part of a desert. Now a desert is defined as a place that receives a certain maximum amount of rainfall. But you may not know that it usually takes more than just a lack of water to turn productive land into a desert. There are several specific human activities that when combined with a lack of rainfall encourages desertification. For example, over cultivation, growing more crops than soil can support. The soil loses its nutrients, so it needs either to be fertilized or to be left unused for at least a season. But if neither of these things happens, if these nutrients in the soil don’ t get replaced, the damaged soil stops producing. Another cause of desertification is overgrazing. That’s when the grasses and trees and shrubs of an area are expected to feed more animals than they reasonably can. Too many animals eating in the same area will kill the vegetation. And because it’s the roots of this vegetation that hold much of the soil together, when too much of the vegetation dies, the soil erodes. But maybe the most ironic example of human behavior that can lead to desertification is irrigation. It may seem to run counter to common sense to say that introducing water into an area can cause it to become more like a desert But there are plenty of bad irrigation practices that do just that Bringing in too much salty water and then not providing adequate drainage for it will fill the soil with salt, and turn the area into a desert.
Now listen to the following recording and answer questions 16 to 19.
16. How is the soil damaged by over cultivation?
17. What is overgrazing?
18. How does overgrazing damage soil?
19. According to the speaker, what is the main problem with irrigation?
选项
A、It can cause flooding
B、It can carry diseases that affect animals.
C、It can introduce too much salt into the soil.
D、It can divert water from important crops.
答案
C
解析
细节题。根据Bringing in too much salty water and then not providing adequate drainage for it will fill the soil with salt, and turn the area into a desert可知灌溉含盐的水,且没有引流,也会导致土地沙漠化。因此,正确答案是C。
转载请注明原文地址:https://kaotiyun.com/show/JrH7777K
0
大学英语六级
相关试题推荐
A、Colombia.B、Peru.C、Bolivia.D、Vietnam.A细节题。根据文中的“ColombiaisthesourceofmostofthecocaineandheroinusedintheU.S.Dr
WhyIBecameaTeacher:toPassonMyLoveofLiteratureA)Likelotsofpeople,IneverthoughtI’dbeateacherwhenIwasats
A、Theyagreedtokillallthesickbirds.B、Theyagreedtoreportanybreakoutofbirdflu.C、Theyendorsedabirdflu-preventio
A、ImprovingspokenEnglish.B、Sharpeninglisteningability.C、Enlargingidiomvocabulary.D、Improvingwritingskills.D细节题。对话中依次
A、WilliamCarlosWilliams.B、Apoem.C、Ashortstorywriter.D、Itdoesn’tmentioned.A细节题。男士问女士的展示是关于什么的,女士回答WilliamCarlosWill
A、Tropicalinsects.B、Decayedleaves.C、Treeresin.D、Birdfeathers.C细节题。题目问琥珀是如何形成的,根据Amberisreallyfossilizedtreeresin.可知
A、Bothofthemcanspiceone’slife.B、Neitherofthemismeaningful.C、They’rebothjustwaystoescapefromreallife.D、They
A、Theanimalsoverfertilizethesoil.B、Deadplantrootscan’tholdthesoiltogether.C、Thewrongtypesofplantsareleftsta
AnimalsontheMoveA)Itlookedlikeascenefrom"Jaws"butwithoutthedramaticmusic.Ahugesharkwasslowlyswimmingthrou
Articlesinmagazinesandnewspapersandspecialreportsonradioandtelevision【B1】______theconcernofmanyAmericansaboutth
随机试题
阅读下面文字,回答问题。子不闻至德之世乎?饭粝粱,啜藜藿,饮食未侈也;夏葛衣,冬鹿裘,衣服未备也;土阶三尺,茆茨不剪,宫室未美也;为衢室之访,为总章之听,故曰“皇帝清问下民”,其分未严也;尧让许由而许由逃,舜让石户之农而石户之农入海,终身不反,其
简述相邻关系的概念和特征。
按照我国现行规定,建筑施工企业应当至少每月向劳动者支付一次工资,()末结清劳动者剩余应得的工资。
根据下面材料回答问题。2012年建材工业增加值同比增长11.5%,增速回落8个百分点,占全国工业增加值的6.6%。全年水泥产量21.8亿吨、同比增长7.4%,陶瓷砖92亿平方米、同比增长9.4%,天然花岗岩石材4.1亿平方米,同比增长27.2%。平板玻璃
按照已知的信息和熟悉的规则进行的思维称为()
我国公安队伍能有统一的认识、统一的部署、统一的行动,是与有统一的()分不开的。
列宁说:“没有革命的理论,就没有革命的运动。”这句话揭示了理论对实践的巨大指导作用。之所以说理论对实践具有巨大的指导作用,是因为()
Duringthelast15years,theEarth’ssurfacetemperatureroseatarateof0.04°Cadecade,farslowerthanthe0.18℃increase
以下能用宏而不需要VBA就能完成的操作是()。
1.目前,垃圾短信给人们的生活带来了许多的麻烦与困扰;2.这种现象产生的原因;3.如何解决这个问题。MyViewonSpamMessage
最新回复
(
0
)