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
2023-08-10
81
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/2913501.html
相关试题推荐
[originaltext](9-1)ArecentInternationalLaborOrganizationreportsaysthe
[originaltext](9-1)ArecentInternationalLaborOrganizationreportsaysthe
[originaltext](9-1)ArecentInternationalLaborOrganizationreportsaysthe
[originaltext]ResearchershavefoundnotjustadiversityprobleminHollywo
[originaltext]ResearchershavefoundnotjustadiversityprobleminHollywo
[originaltext]Areportonsleepandnutritionreleasedthismonthfoundthat
[originaltext]Areportonsleepandnutritionreleasedthismonthfoundthat
[originaltext]ResearchershavefoundnotjustadiversityprobleminHollywo
[originaltext]ResearchershavefoundnotjustadiversityprobleminHollywo
[originaltext]M:(5)Yousayyourshophasbeendoingwell.Couldyougivemesom
随机试题
TheNationalDayofCanadaisA、July1st.B、July4th.C、January26th.D、June5th.
Sportisnotonlyphysicallychallenging,butitcanalsobementallychalle
影响袋式除尘器压力损失大小的因素中,下列哪一项是错误的?()A.除尘器设在风
A.π-2 B.π+2 C.π D.π+1
下列属于非标准化债权资产的有()。A.国债 B.承兑汇票 C.信托贷
患者,男性,40岁。进行性贫血,发热,骨痛。双腋下淋巴结如花生米大小,肝肋下1c
教师的心理健康问题主要表现为()和()。
在国外,征信机构更新个人信息的频率大致有()。A:实时更新B:次日更新C:次
A.赤芍 B.山豆根 C.白芷 D.板蓝根 E.细辛切面白色或灰白色,具
窝沟封闭成功的关键是()A.酸蚀剂量要大 B.酸蚀时间要充足 C.牙面要彻底
最新回复
(
0
)