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、Too many animals eating the plants in one small area. B、Planting too much vegetation in one small area. C、Too many people buil
A、Too many animals eating the plants in one small area. B、Planting too much vegetation in one small area. C、Too many people buil
admin
2018-02-13
98
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、Too many animals eating the plants in one small area.
B、Planting too much vegetation in one small area.
C、Too many people building houses in one small area.
D、Bringing together the wrong kinds of animals and plants.
答案
A
解析
细节题。根据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.可知,过度放牧也就是在有草树等植物的一片区域饲养过多的动物。因此,正确答案是A。
转载请注明原文地址:https://kaotiyun.com/show/oQT7777K
0
大学英语六级
相关试题推荐
Theestimatesofthenumbersofhome-schooledchildrenvarywidely.TheU.S.DepartmentofEducationestimatesthereare250,00
Theestimatesofthenumbersofhome-schooledchildrenvarywidely.TheU.S.DepartmentofEducationestimatesthereare250,00
MarieCuriewasthefirstfemaleprofessoratSevres,acollegeforgirlswhowantedtoteachhighereducation.Thesetwenty-yea
A、13million.B、30million.C、14million.D、40million.B细节题。文中说图书馆有超过3000万本书籍和画册。
A、Takingtheair.B、Bybus.C、OnradioandTV.D、Attheairport.C细节题。原文中对“ontheair”做了解释:通过收音机,电视等媒介方式进行远程教学。
A、Becauseitwasdifficulttogetthepicturesandsoundtogether.B、Becausetheaudienceslikedthesilentform.C、Becausethe
Biologically,thereisonlyonequalitywhichdistinguishesusfromanimals:theabilitytolaugh.Inauniversewhichappearst
A、Thenumberofsunspotsincreasedanddecreasedinapattern.B、Theshapeofthesunspotschangedastheymoveacrossthesurfa
A、Washingdishes.B、Writingforlocalnewspapers.C、Mowingthelawn.D、Repairingtheplumbers.C本题问的是男士的工作经验。男士说他每周都做一些诸如洗车的事情,如
A、Everybodywillfeelcentered.B、Nobodywillgetbored.C、Nobodywillbeexcluded.D、Everybodywilltalkalot.CDr.Wood在讲座中提到,
随机试题
阅读材料,回答问题。材料1中华民族是世界上伟大的民族,有着5000多年源远流长的文明历史,为人类文明进步作出了不可磨灭的贡献。1840年鸦片战争以后,中国逐步成为半殖民地半封建社会,国家蒙辱、人民蒙难、文明蒙尘,中华民族遭受了前所未有的
有溃疡性结肠炎的治疗中,糖皮质激素适用于
枕骨摄影的最佳体位是
细胞水肿,电镜下的形态改变是
下列哪项不符合二期愈合的特点()。
调查人群龋病流行情况的分组不包括
关于药物经济学中的成本A、成本B、直接成本C、间接成本D、隐性成本E、以上均不是因诊断治疗过程中带来的担忧、痛苦属于
背景某安装公司承包一演艺中心的空调工程,演艺中心地处江边(距离江边100m),空调工程设备材料:双工况冷水机组(650Rt)、蓄冰槽、江水源热泵机组、燃气锅炉、低噪声冷却塔(650t/h)、板式热交换机、水泵、空调箱、风机盘管、各类阀门(DN20
注意的品质特征有注意的广度、______、______和注意的转移等。
衡量一个教师是否成熟的标志之一是其能否自觉()。
最新回复
(
0
)