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
The cause of the decline of North Africa is popularly attributed to climatic changes, the theory being that the area became hott
The cause of the decline of North Africa is popularly attributed to climatic changes, the theory being that the area became hott
admin
2010-10-14
22
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.
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://jikaoti.com/ti/OelFFFFM
0
大学英语四级
相关试题推荐
Afewmonthsago,millionsofpeopleinLondonheard【B1】______alloverthetown.Emergencyservices,theFireDepartments,theP
Afewmonthsago,millionsofpeopleinLondonheard【B1】______alloverthetown.Emergencyservices,theFireDepartments,theP
A、Hethinkssheshouldvisithercousin.B、Hercousindoesn’tvisitveryoften.C、Hercousinisfeelingalotbettertoday.D、He
Inthisnewera,thesinglemostimmediateandmostseriouschallengetoAmericatraditionalidentitycomesfromtheimmenseand
Whenwethinkofentrepreneurs,mostofusimagine【C1】______,successful,over-achieverslikeBillGatesofMicrosoft,RichardB
Longbusridesareliketelevisionshows.Theyhaveabeginning,amiddle,andanend-withcommercialsthrownineverythreeorfou
Longbusridesareliketelevisionshows.Theyhaveabeginning,amiddle,andanend-withcommercialsthrownineverythreeorfou
A、Hemustaskfortheagreementofthelandlord.B、Hemustcollecttheentireluggageinthehouse.C、Hemusthaveadiscussion
A、Holdapressconference.B、BlametheformerCEO.C、Askformoreemployees.D、Reorganize.B题目询问第一封信的内容是什么。关键是听到“Blameyourform
随机试题
疫毒痢的治法是
45岁,女性,外阴口腔反复溃疡3年,结膜充血1个月来诊。查体:舌面上多个溃疡,黄色,较深,左眼充血,右侧4字征阳性。结果提示胸片正常,心电图正常,针刺反应阳性,目前诊断为
鸭浆膜炎的特征性病变是
月经过多是指
对银行机构流动性监管内容有()。
莫扎特的造访赵丽宏不是所有的音乐都可以把你引进天堂,音乐家也有烦躁不安的时候。但是,有一位音乐家例外,那便是莫扎特。在我写这篇文章的时候,我家的音响中正播放着莫扎特
供受文者使用的具有法定效用的正式文本,格式规范并具备各种生效标志的稿本称作()。
公民购买债券、银行储蓄、参加商业保险的共同点是——。
StevenWenttoLondonby______.StevenlosthisWayin______.
Forshopaholics,thepost-【D1】______periodmeansonlyonething:sales.Acrossthecountry,pricesareslashonclothing,【D2】__
最新回复
(
0
)