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
2017-02-24
33
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/i9U7777K
0
大学英语六级
相关试题推荐
Afterdecadesofstaringatapes,FransdeWaalhaswrittenabookaboutwhathumansseewhentheywatchchimpanzees.Thesecrea
EatingOurYoung[A]AtFeltonvilleSchoolofArtsandSciences,amiddleschoolinapoorneighborhoodofPhiladelphia,thescho
EatingOurYoung[A]AtFeltonvilleSchoolofArtsandSciences,amiddleschoolinapoorneighborhoodofPhiladelphia,thescho
A、Itcombinesdifferentfeelingstogether.B、Itcanexpresssomeveryconfusingfeelings.C、Itexaggeratessomespecialfeelings
A、Gowiththewomanforfearofoversleeping.B、Stayattheapartmentandsleepforawhile.C、Stayupandgoforthemeeting.D
A、Thewomanshouldtryherluckinthebanknearby.B、Thebankaroundthecornerisnotopentoday.C、Thewomanshouldusedolla
Thenewyearalwaysbringswithitaculturaltraditionofnewpossibilities.Weseeitasachancefor【B1】______.Webegintod
Receivingvisitorsandguestsisanimportantpartofthesecretary’sdailyroutineintheoffice.Thereisacertain【B1】______f
Receivingvisitorsandguestsisanimportantpartofthesecretary’sdailyroutineintheoffice.Thereisacertain【B1】______f
Receivingvisitorsandguestsisanimportantpartofthesecretary’sdailyroutineintheoffice.Thereisacertain【B1】______f
随机试题
患者,男。两日来发热微恶寒,口苦,胁痛,尿短黄,大便黏臭,舌红苔薄白,脉数。其证候是
肉芽组织与肉芽肿的光镜下区别在于
患者腰痛多年,时轻时重,伴双下肢痛。10天前搬重物后腰腿痛加剧,并出现麻木与排尿困难。查体:腰运动受限,椎旁压痛向下肢放射,直腿抬高和加强试验阳性,马鞍区痛觉减退。最主要的治疗措施是
财务内部收益率是使项目在计算期内各年净现金流量累计净现值()时的折现率。
下列句子中的标点符号使用都正确的一项是()。
进程被创建后即进入()排队。
购买力平价理论是以()为理论基础
下面程序是一个计时器,从1000秒开始倒计时,直到为0结束。在界面上有两个按钮,一个可以暂停计时,另一个可以继续已经暂停的计时。请更正题中带下划线的部分。注意:不改动程序的结构,不得增行或删行importjava.awt.*;im
A、 B、 C、 C
Jordanhad3hitsinhisfirst4baseballgamesand4hitsinhisnext4games.WhatistheaveragenumberofhitsJordanhadin
最新回复
(
0
)