如何写英语作文关于使用水的作文
题目
如何写英语作文关于使用水的作文
答案
Uses of Water
Water is one of the most vital natural resources for all life on Earth.The availability and quality of water always have played an important part in determining not only where people can live,but also their quality of life.Even though there always has been plenty of fresh water on Earth,water has not always been available when and where it is needed,nor is it always of suitable quality for all uses.Water must be considered as a finite resource that has limits and boundaries to its availability and suitability for use.
result between and among the various uses.
The balance between supply and demand for water is a delicate one.The availability of usable water has and will continue to dictate where and to what extent development will occur.Water must be in sufficient supply for an area to develop,and an area cannot continue to develop if water demand far outstrips available supply.Further,a water supply will be called upon to meet an array of offstream uses (in which the water is withdrawn from the source) in addition to instream uses (in which the water remains in place).Figure 1 represents the demands on water as a tug-of-war among the various offstream and instream uses.
Traditionally,water management in the United States focused on expanding or manipulating the country's supplies of fresh water to meet the needs of users.A number of large dams were built during the early twentieth century to increase the supply of fresh water for any given time and place.This era of building large dams has passed.In the twenty-first century,the finite water supply and established infrastructure require that demand be managed more effectively within the available sustainable supply.Water-use information can be used to evaluate the impacts of population growth and the effectiveness of alternative water management policies,regulations,and conservation activities.
The Water-Use Cycle
Water is constantly in motion by way of the hydrologic cycle.Water evaporates as vapor from oceans,lakes,and rivers; is transpired from plants; condenses in the air and falls as precipitation; and then moves over and through the ground into waterbodies,where the cycle begins again.*
The water-use cycle is composed of the water cycle with the added influence of human activity.Dams,reservoirs,canals,aqueducts ,withdrawal pipes in rivers,and groundwater wells all reveal that humans have a major impact on the water cycle.In the water-use cycle,water moves from a source to a point of use,and then to a point of disposition.The sources of water are either surface water or groundwater.Water is withdrawn and moved from a source to a point of use,such as an industry,restaurant,home,or farm.After water is used,it must be disposed of (or sometimes,reused).Used water is either directly returned to the environment or passes through a treatment processing plant before being returned.
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点
- Who is TOM?A:the boy in blue.B,the boy on blue.C,Yes,he is.D,No ,he is not.
- On being told by an assistant that the dress was sold,the woman returned the following morning dress
- a^1+a^2+a^3+..+a^n等于多少
- 1.甲乙两车分别从AB两地开出,4小时后相遇,然后各自继续行3小时,此时甲车距B地10千米,乙车距A地80千米.甲车到B地时,乙车多久才能到A地?
- 已知如图所示电稳压管的稳压电压Uz=6V,最小稳定电流Izmin=5mA.最大稳定电流IZmax=25mA.分别计算U1为10V,15V,35V三种情况下输出电压Uo的值
- 1、平面镜有把射来的太阳光再折射到另一方向去.
- 把1、2、3、4、5、6、7、8、9这九个数填入下面的九个方格内,每个数只能用一次,使等式成立. □×□×(□+□+□+□)×(□+□-□)=2002.
- be going to不是近期安排好的事情吗?那为什么这一句是i think we will have to go up again?
- a与one的用法区别
- 如图所示,弹簧测力计下挂着一重物A,烧杯中盛有溶液B,试根据要求回答下列问题: (1)若A为铁块,B为稀硫酸,则将A放入B中,过一会儿,弹簧秤的读数将(填“变大”“变小”或“不