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
18
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
[originaltext]Aswithsomanyotherthingsinlife,exercisemayworkbest
Thedebateoverwhetherdogsorcatsmakebetterpetswasgivenanewdimensi
目前我国的期货结算机构()。A、独立于期货交易所B、只提供结算服务C、属于期货交易所的内部机构D、以上都不对C目前我国的期货结算机构属于期货交易
A. B. C. D.
百善孝为先,晋代的郭巨为节省粮食供养母亲而埋掉儿子。即24孝故事之“埋儿奉母”。
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
二氧化硫是造成酸雨的主要原因。某地区饱受酸雨困扰,为改善这一状况,该地区1~6
一般来说,在宏观经济运行良好的条件下,投资和消费增加,需求将(),商品的价格和股
(2021年真题)关于税制要素的说法,正确的有()。A.课税对象是指税法规定的
治疗重度一氧化碳中毒首选的氧疗是A.高压氧舱 B.面罩吸氧 C.人工呼吸
最新回复
(
0
)