首页
登录
职称英语
The cause of the decline of North Africa is popularly attributed to climatic
The cause of the decline of North Africa is popularly attributed to climatic
游客
2024-02-23
25
管理
问题
The cause of the decline of North Africa is popularly attributed to climatic changes, the theory being that the area became hotter and drier and the people were forced to abandon a thriving civilization. However, some geologists, after carefully weighing the evidence, have challenged the conclusion that the climate has changed in any important way since Roman tithes. Although climatological factors may also have contributed, it was man who destroyed the balance of nature responsible for maintaining soil fertility and moisture.
Why is it that under certain circumstances, the plant cover is unable to regenerate itself, thus setting the stage for serious erosion(腐蚀)? To answer this question, let us take an extreme example, the destruction of tropical rain forests. In general, the equatorial(赤道附近的)soil is poor: forests can exist in these regions only because they are part of a balanced cycle. All that the forest produces is returned to the forest. The organic matter that falls from the trees constitutes the humus(腐殖土)that the forest requires. When people cut down all the trees to make room for crops, the soil is laid bare and, deprived of shade, heats up. An increase in soil temperature increases the rate of decomposition(分解)of organic matter. Organic nitrogen(氮)is converted into soluble ammonia(氨)and nitrates(硝酸盐), which the rains quickly leach(沥滤,溶滤)away. It has been calculated that a rise in temperature from 77 to 78.8 may increase the loss of nitrogen by fifteen to twenty pounds per acre per year. With the fertility of soil destroyed, an irreversible change from forest to desert can be initiated. [br] From this passage we can infer that the author’s attitude toward the theory of some geologists(Line 3, Para. 1)is ______.
选项
A、approval
B、disapproval
C、indifference
D、displeasure
答案
A
解析
文章一开头提出人们普遍认为气候是导致北非衰落的因素,但第2句的however表明地质学家的观点与此不同,之后本文主要讨论地质学家观点的合理性,由此可证明作者是赞同他们的观点的。
转载请注明原文地址:https://tihaiku.com/zcyy/3474737.html
相关试题推荐
Thedeclineinmoralstandards--whichhaslongconcernedsocialanalysts--ha
Thedeclineinmoralstandards--whichhaslongconcernedsocialanalysts--ha
Thedeclineinmoralstandards--whichhaslongconcernedsocialanalysts--ha
Thedeclineinmoralstandards--whichhaslongconcernedsocialanalysts--ha
Thedeclineinmoralstandards--whichhaslongconcernedsocialanalysts--ha
Thedeclineinmoralstandards--whichhaslongconcernedsocialanalysts--ha
Someobservershaveattributedthedramaticgrowthintemporaryemploymentt
Someobservershaveattributedthedramaticgrowthintemporaryemploymentt
[originaltext]CamerooninWestAfricaisanationof24separatelanguages
[originaltext]CamerooninWestAfricaisanationof24separatelanguages
随机试题
【B1】[br]【B3】A、ThereforeB、NeverthelessC、HoweverD、MoreoverD逻辑衔接题。结婚率上升是对更多的人
对于桥梁工程原材料中的钢筋的说法,错误的有()。A.钢筋的级别、种类和直径
一般公共建筑中,如影院、会堂、商店等常采用的送风方式是()。A.上送式 B
下列岩石中,最容易遇水软化的是( )。A.石灰砂岩 B.石灰岩 C.黏土岩
某三级公路进行升级改造,为了解路基状况,检测机构用承载板法测定土基回弹模量。请回
下列各项,不具有活血疗伤功效的药物是()A.丹参 B.苏木 C.血
香加皮的功效是A.利水消肿,祛风湿,强筋骨 B.利水通淋,清热排脓 C.利
A.木兰科B.豆科C.鸢尾科D.菊科E.香蒲科西红花来源于
下列不属于胃食管反流病并发症的是( )。A.食管狭窄 B.食管憩室 C.上
基础心理学是研究()。 (A)正常成人心理现象的心理学基础学科 (B
最新回复
(
0
)