首页
登录
职称英语
[originaltext] Today, I’d like to talk about some of the changes land can und
[originaltext] Today, I’d like to talk about some of the changes land can und
游客
2023-08-13
32
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 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、The animals overfertilize the soil.
B、Dead plant roots can’t hold the soil together.
C、The wrong types of plants are left standing.
D、There is a buildup of plant and animal matter.
答案
B
解析
细节题。根据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.可知,过度放牧会严重破坏植被,而这些植被的根能够凝沙固土,一旦植被被破坏,土地就会退化。因此,正确答案是B。
转载请注明原文地址:https://tihaiku.com/zcyy/2921205.html
相关试题推荐
[originaltext]W:Whenwasthelasttimeyouwentforawalkinyourlocalpark?
[originaltext]W:Whenwasthelasttimeyouwentforawalkinyourlocalpark?
[originaltext]W:Whenwasthelasttimeyouwentforawalkinyourlocalpark?
[originaltext][19]Imagineabigexplosionasyouclimbthrough3,000ft.I
[originaltext][19]Imagineabigexplosionasyouclimbthrough3,000ft.I
[originaltext]W:HelloLadiesandGentlemen,itisagreatpleasuretohaveSco
[originaltext]W:HelloLadiesandGentlemen,itisagreatpleasuretohaveSco
[originaltext]W:HelloLadiesandGentlemen,itisagreatpleasuretohaveSco
[originaltext]E-booksarebringingaboutaprofoundrevolutioninthewayb
[originaltext]E-booksarebringingaboutaprofoundrevolutioninthewayb
随机试题
[originaltext]M:(1)CaitlinFriedmanoffersadviceonbeingasmartwoman-in-c
WhatisthenameofthebookJennyisreading?[br][originaltext]M:Hey,Jenny
【S1】[br]【S2】make→taketakeadvantageof是固定搭配,意为“利用”。
Thepresidentistogiveaformal____at
阅读下列说明,回答问题1至问题3,将解答填入答题纸的对应栏内。【说明】图1-1是
林可霉素与吗啡合用()A:增加后者的用药剂量 B:拮抗,不宜合用 C:产生
关于清热药主要药理作用叙述错误的是A:抗病原微生物B:抗毒素C:发汗D:解
(三) 某城市因道路拓宽需拆迁一幢建于2000年,建筑面积为8000m2
科学发展观形成的现实依据是A.社会主义初级阶段的基本国情 B.新世纪新的阶段性
关于全身疾病患者的牙周治疗,下列哪一项是不正确的A.有严重并发症的糖尿病患者,只
最新回复
(
0
)