首页
登录
职称英语
Scientists say there has been a severe decrease in the amount of water in La
Scientists say there has been a severe decrease in the amount of water in La
游客
2023-09-16
19
管理
问题
Scientists say there has been a severe decrease in the amount of water in Lake Chad in northern Africa in the last thirty years. They report that nature and humans share equal blame for this loss.
In 1963 the fresh water lake covered twenty-five-thousand-square kilometers. Now the lake is only about five percent of that size. It measures only about one-thousand-three-hundred square kilometers in the dry season.
Four nations surround Lake Chad. People in Niger, Nigeria, Chad, and Cameroon use it for water, fish and plant life.
Michael Coe and Jonathan Foley are water experts at the University of Wisconsin in Madison. They reported about Lake Chad in the Journal of Geophysical Research. They say the area has suffered from a lack of heavy rain for more than thirty years. This has forced people to build systems to carry water to dry land. These irrigation systems further decrease the lake.
Mister Coe says Lake Chad will be only a small body of water in the future. He says people still can get water from the lake to drink and for crops. But he says the lake will no longer provide a healthy environment for fish and plant life.
The researchers used a computer to study what caused the water loss. Their computer study estimated the climate and amount of water in the area. The estimate started with the early 1960s. Then the researchers compared the estimates with the area’s recorded climate and water supply for the same period.
The computer study showed results similar to the recorded ones for the first twenty years. But there was a big change in the 1980s. At that time, the lake got smaller much faster than the computer research had estimated.
The researchers say major irrigation systems were built in the 1980s. The systems took water from two rivers that low into Lake Chad. The Chari and Logone rivers carry most of the water that enters the lake. The study showed the increased irrigation reduced the flow in the two rivers. Climate changes also were responsible for the reduction. Today the flow of the two rivers has been reduced by almost seventy-five percent.
Scientists say the problem is expected to worsen in the coming years as the population and demand for water continue to increase.
选项
A、Demonstrating the serious weather condition around Lake Chad.
B、Introducing people’s activity around Lake Chad.
C、Analyzing of the factors that cause water decreases in Lake Chad.
D、Introducing scientists’ work about water condition in Lake Chad.
答案
C
解析
主题题。A只是文中提及的自然因素;文中提及people’s activity只是为了说明人为因素;介绍科学家的工作也是为了分析原因。因此A,B,D均为错误答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3019403.html
相关试题推荐
Theholidaysarethemostwastefultimeoftheyear.Theamountofwastepro
Theholidaysarethemostwastefultimeoftheyear.Theamountofwastepro
Theholidaysarethemostwastefultimeoftheyear.Theamountofwastepro
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Withthework(do)______,thesescientistsbegantoplananotherresearchproject
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
随机试题
HowtoSucceedinYourLiteratureClassCollegeliteratu
Myjobwastomakeclassroomobservationsandencourageatrainingprogramt
Inacompetitiveeconomy,theconsumerusuallyhasthechoiceofseveraldif
EndangeredPeoplesA)Today,itisnotdistance,butcult
安徽池州的()号称“戏剧活化石”。A.黄梅戏 B.徽剧 C.庐剧 D.傩
十字花科的拟南芥是雌雄同体的植物,常作为遗传学研究的模式植物。野生型拟南芥的种皮
患儿,4岁。发热咳嗽3天。发热恶风,头痛有汗,鼻塞流浊涕,咳嗽,气促,咽红肿,喉
2018年4月,某审计组对甲公司2017年度财务收支情况进行了审计。有关情况和资
根据《村民委员会组织法》,关于村民会议的说法,正确的是()A.有十分之一
某列车长度为600m,列车在直线段运行时距轨道中心线10m测得的最大A声级为82
最新回复
(
0
)