首页
登录
职称英语
[originaltext] Today, I’d like to talk about some of the changes land can un
[originaltext] Today, I’d like to talk about some of the changes land can un
游客
2024-06-15
4
管理
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 encourage 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 it’s because it’s the roots of this vegetation that hold much of the soil together, when too much of the vegetation dies, the soil corrodes. But maybe the most paradoxical 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 till the soil with salt, and turn the area into a desert.
选项
A、It can cause flooding annually.
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
According to the speaker,what is the main problem with irrigation?
转载请注明原文地址:https://tihaiku.com/zcyy/3635303.html
相关试题推荐
[originaltext]W:I’mlosingmysleep.Ifeeltiredandsleepyallthetime.I’ve
[originaltext]M:I’veheardthatyouplaytheviolinverywell.W:Thankyou.Il
[originaltext]M:I’veheardthatyouplaytheviolinverywell.W:Thankyou.Il
[originaltext]W:HaveyoumetMargeyet?M:Wearefromthesamehometown.Q:What
[originaltext]W:IwanttobuyboththeskirtandtheT-shirt.Howmucharethey
[originaltext]W:Paul,youaremovingtoNewYork?M:Yeah.W:Why?M:BecauseIwa
[originaltext]W:Paul,youaremovingtoNewYork?M:Yeah.W:Why?M:BecauseIwa
[originaltext]W:Hello,ABCCompany.MayIhelpyou?M:Hello.ThisisLiMing.M
[originaltext]W:What’syouradvicetoyoungpeoplewhoarethinkingaboutself-
[originaltext]W:WherecanIfindasupermarket?M:There’sonearoundthecorner
随机试题
Summerhillbeganasanexperimentalschool,Itisnolongersuch;itisnow
WhicheventisregardedasaturningpointintheAmericanWarofIndependence?A
[originaltext]Thefoodweeatseemstohaveproducedprofoundeffectsonou
微观经济学最终解决的问题是( )。 A.资源最佳配置 B.资源最佳利用
熊去氧胆酸的适应症不包括()A:治疗脂肪痢 B:胆色素结石 C:胆固醇型结
《医疗机构从业人员行为规范》的执行和实施情况,应列入A.定期考核和医德考评 B
一位癌症患者接受环磷酰胺、多柔比星、顺铂4个疗程后,病情仍无改善。此时该患者的血
A.两玩具小车的速度大小相同 B.两玩具小车各运动20m,所用时间相同 C.
隐性肝性脑病病人的临床特点是 A.轻度性格改变B.轻度行为改变C.应答尚准确,
在古代的东西方,学校教学的组织形式一般都是()。 A.个别教学制 B.分组教
最新回复
(
0
)