急求英语作文Why do we learn English?
If you ask why we should learn English,my answer will be simple and clear.Now let me enumerate the reasons one by one in the following.First of all,English has become an international language.It plays a more and more important part in the world,especially on business and association among countries.If you speak English,you can make a round the world trip without being misunderstood.You can easily make yourself understood.Besides,English can reduce the trouble and save money when you’re making a world trip.In another hand,most valuable books,newspaper and magazines are written in English.If you hope to get more knowledge and useful information,you must learn English and try to master it as well as handling skillfully.You can enjoy some famous works and learn what the different customs are in the foreign countries with the help of knowing English.Furthermore,it’s necessary to learn English with China’s entry to WTO.That can make us know more about WTO and how to use the right in WTO to solve the trade problems.As we enter a new millennium,the ability and the need to understand and communicate with each other has become increasingly important that we must learn English.Without mastering it,you can no more find a place to settle in.
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You may wonder why you must study English at school, especially at this school of technology. At some universities, for instance, students do not have to study English at all if they do not want to. <...
Because We learn English can talk with foreigners.English is the most-widely used language in th World.
In order to communicate with other people effectively and learn the advance science and technol...
扫描下载二维码why do we study English
English is an important foreign language to master,not merely because it is the language of Britain or the United States,but because it provides ready access to world scolarship and the world trade.
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Just because every teenagers and kids around us do that, we do the same thing.
扫描下载二维码1.2 What Is Calculus and Why do we Study it?
1.2 What Is Calculus and Why do we Study it?
Calculus is the study of how things change. It provides a framework for modeling systems in which there is change, and a way to deduce the predictions of such models.
I have been around for a while, and know how things change, more or less. What can calculus add to that?
I am sure you know lots about how things change. And you have a qualitative notion of calculus. For example the concept of speed of motion is a notion straight from calculus, though it surely existed long before calculus did and you know lots about it.
So what does calculus add for me?
It provides a way for us to construct relatively simple quantitative models of change, and to deduce their consequences.
To what end?
With this you get the ability to find the effects of changing conditions on the system being investigated. By studying these, you can learn how to control the system to do make it do what you want it to do. Calculus, by giving engineers and you the ability to model and control systems gives them (and potentially you) extraordinary power over the material world.
The development of calculus and its applications to physics and engineering is probably the most significant factor in the development of modern science beyond where it was in the days of Archimedes. And this was responsible for the industrial revolution and everything that has followed from it including almost all the major advances of the last few centuries.
Are you trying to claim that I will know enough about calculus to model systems and deduce enough to control them?
If you had asked me this question ten years ago I would have said no. Now it is within the realm of possibility, for some non-trivial systems, with your use of your laptop or desk computer.
OK, but how does calculus models change? What is calculus like?
The fundamental idea of calculus is to study change by studying &instantaneous& change, by which we mean changes over tiny intervals of time.
And what good is that?
It turns out that such changes tend to be lots simpler than changes over finite intervals of time. This means they are lots easier to model. In fact calculus was invented by Newton, who discovered that acceleration, which means change of speed of objects could be modeled by his relatively simple laws of motion.
This leaves us with the problem of deducing information about the motion of objects from information about their speed or acceleration. And the details of calculus involve the interrelations between the concepts exemplified by speed and acceleration and that represented by position.
So what does one study in learning about calculus?
To begin with you have to have a framework for describing such notions as position speed and acceleration.
Single variable calculus, which is what we begin with, can deal with motion of an object along a fixed path. The more general problem, when motion can take place on a surface, or in space, can be handled by multivariable calculus. We study this latter subject by finding clever tricks for using the one dimensional ideas and methods to handle the more general problems. So single variable calculus is the key to the general problem as well.
When we deal with an object moving along a path, its position varies with time we can describe its position at any time by a single number, which can be the distance in some units from some fixed point on that path, called the &origin& of our coordinate system. (We add a sign to this distance, which will be negative if the object is behind the origin.)
The motion of the object is then characterized by the set of its numerical positions at relevant points in time.
The set of positions and times that we use to describe motion is what we call a function. And similar functions are used to describe the quantities of interest in all the systems to which calculus is applied.
The course here starts with a review of numbers and functions and their properties. You are undoubtedly familiar with much of this, so we have attempted to add unfamiliar material to keep your attention while looking at it.
I will get bogged down if I read about such stuff. Must I?
I would love to have you look at it, since I wrote it, but if you prefer not to, you could undoubtedly get by skipping it, and referring back to it when or if you need to do so. However you will miss the new information, and doing so could blight you forever. (Though I doubt it.)
And what comes after numbers and functions?
A typical course in calculus covers the following topics:
1. How to find the instantaneous change (called the &derivative&) of various functions. (The process of doing so is called &differentiation&.)
2. How to use derivatives to solve various kinds of problems.
3. How to go back from the derivative of a function to the function itself. (This process is called &integration&.)
4. Study of detailed methods for integrating functions of certain kinds.
5. How to use integration to solve various geometric problems, such as computations
of areas and volumes of certain regions.
There are a few other standard topics in such a course. These include description of functions in terms of power series, and the study of when an infinite series &converges& to a number.
So where does this empower me to do what?
It doesn't really do so. The problem is that such courses were first designed
centuries ago, and they were aimed not at empowerment (at that time utterly
impossible) but at familiarizing their audience with ideas and concepts and
notations which allow understanding of more advanced work. Mathematicians and
scientists and engineers use concepts of calculus in all sorts of contexts and
use jargon and notations that, without your learning about calculus, would be
completely inscrutable to you. The study of calculus is normally aimed at giving
you the &mathematical sophistication& to relate to such more advanced
So why this nonsense about empowerment?
This course will try to be different and to aim at empowerment as well as the other usual goals. It may not succeed, but at least will try.
And how will it try to perform this wonder?
Traditional calculus courses emphasize algebraic methods for performing differentiating and integrating. We will describe such methods, but also show how you can perform differentiation and integration (and also solution of ordinary differential equations) on a computer spreadsheet with a tolerable amount of effort. We will also supply applets which do the same automatically with even less effort. With these applets, or a spreadsheet, you can apply the tools of calculus with greater ease and flexibility than has been possible before. (There are more advanced programs that are often available, such as MAPLE and Mathematica, which allow you to do much more with similar ease.) With them you can deduce the consequences of models of various kinds in a wide variety of contexts.
Also, we will put much greater emphasis on modeling systems. With ideas on modeling and methods for solving the differential equations they lead to, you can achieve the empowerment we have claimed.
And I will be able to use this to some worthwhile end?
Okay, probably not. But you might. And also you might be provoked to learn more about the systems you want to study or about mathematics, to improve your chances to do so. Also you might be able to understand the probable consequences of models a little better than you do now.
Well, what is in the introductory chapter on numbers?
We start with the natural numbers (1,2,3,...,) and note how the operations of subtraction, division and taking the square root lead us to extending our number system to include negative numbers, fractions (called rational numbers) and complex numbers. We also describe decimal expansions and examine the notion of countability.
And in the chapter about functions?
We start with an abstract definition of a function (as a set of argument-value pairs) and then describe the standard functions. These are those obtained by starting with the identity function (value=argument) and the exponential function, and using various operations on them.
Operations, what operations?
These are addition, subtraction, multiplication, division, substitution and inversion.
But what is the exponential function, and what are substitution and inversion?
Here are one sentence answers: if you want to know more read the chapter!
The exponential function is mysteriously defined using calculus: it is the function that is its own derivative, defined to have the value 1 at argument 0. It turns out, however, to be something you have seen before. And it turns out to bear a close relation to the sine function of trigonometry.
Substitution of one function f into another g produces a new function, the function defined to have, at argument x, the value of f at an argument which is the value of g at argument x. This is simpler than it sounds.
An inverse of a function is a function obtained by switching its values with its arguments. For example the square function, usually written as x2 has the square root function as an inverse.
In the immortal words of Father William to his nephew, as penned by Lewis Carroll, who was a mathematician:
I have answered three questions and that is enough,
Said the sage, don&t give yourself airs.
Do you think I can listen all day to such stuff?
Be off or I&ll kick you downstairs!你现在的位置 : &
初二英语作文：Why Do We Study English?
　　English is one of the most widely used languages in the world. It is spoken by nearly three hundred million people： in England, the United States, Australia, Canada and many other countries. It is one of the working languages at international meetings and is more used than the others. It is said that 60 percent of the world&#39;s radio broadcasts and 70 percent of the world&#39;s mail are in English. Millions of books and magazines are written in English, too. English is really a bridge to knowledge. With the help of English we can learn modern science and technology faster and better form the developed countries. In this way we can serve our country better.
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热门话题推荐急需一篇英语演讲稿 要说3-4分钟，字数大概200词吧 题目是 Why do we study?_百度知道
急需一篇英语演讲稿 要说3-4分钟，字数大概200词吧 题目是 Why do we study?
更能展示，字数大概200词吧题目是 Why do we study，适合与手势结合? 虽然是大学的英语演讲比赛，且有特色，但希望内容能浅显易懂急需一篇英语演讲稿 要说3-4分钟！跪求英语大神
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it&#39;ll ll come across a lot of things you won&#39. You&#39, it&#39,there are plenty of adults who pretend to know everything.It&#39,then what can you do. Humans naturally want to study. in this world? No matter how much you study. People who are neither curious nor inquisitive are not humansA teacher said that studying hard. the moment you lose your curiosity is the moment you berll wanna know more. Fun things, if you study then you can do anything. Studying. whether it&#39;re just liars. Mt try to understand the world you live in. They&#39, there will always be things you won&#39;t understand. When that happens. If you don&#39;s something you do to become a great person,you&#39. Bs getting into a good college or getting into a good company,you&#39. Is something you should want to do? Studying is not something you have to do. They&#39, getting into a good college and then getting into a good company is meaningless, then whys not something t know or comprehend
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太给力了，你的回答完美地解决了我的问题，非常感谢！
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