词汇语法
词汇语法
You will never gain success __________ you are fully devoted to your work.
A:when B:because C:after D:unless
Text 4
Over the past few decades, there has been a considerable increase in the use of mathematical analysis, both for solving everyday problems and for theoretical developments of many disciplines. For example, economics, biology, geography and medicine have all seen a considerable increase in the use of quantitative techniques. Twenty years ago applied mathematics meant the application of mathematics to problems in mechanics and little else--now, applied mathematics, or as many people prefer to call it, applicable mathematics, could refer to the use of mathematics in many varied areas. The one unifying theme that these applications have is that of mathematical modeling, by which we mean the construction of a mathematical model to describe the situation under study. This process of changing a real life problem into a mathematical one is not at all easy, we hasten to add, although one of the overall aims of this book is to improve your ability as a mathematical modeler.
There have been many books written during the past decade on the topic of mathematical modeling; all these books have been devoted to explaining and developing mathematical models, but very little space has been given to how to construct mathematical models, that is, how to take a real problem and convert it into a mathematical one. Although we appreciate that we might not yet have the best methods for teaching how to tackle real problems, we do at least regard this mastery of model formulation as a crucial step, and much of this book is devoted to attempting to make you more proficient in this process.
Our basic concept is that applied mathematicians become better modelers through more and more experience of tackling real problems. So in order to get the most out of this book, we stress that you must make a positive effort to tackle the many problems posed before looking at the solutions we have given. To help you to gain confidence in the art of modeling we have divided the book into four distinct sections.
In the first section we describe three different examples of how mathematical analysis has been used to solve practical problems. These are all true accounts of how mathematical analysis has helped to provide solutions. We are not expecting you to do much at this stage, except to read through the case studies carefully, paying particular attention to the way in which the problems have been tackled--the process of translating the problem into a mathematical one.
The second section consists of a series of real problems, together with possible solutions and related problems. Each problem has a clear statement, and we very much encourage you to try to solve these problems in the first place without looking at the solutions we have given. The problems require for solution different levels of mathematics, and you might find you have not yet covered some of the mathematical topics required. In general we have tried to order them, so that the level of mathematics required in the solutions increase as you move through the problems. Remember that we are only giving our solutions and, particularly if you don’ t look at our solution, you might well have a completely different approach which might provide a better solution.
Here, in the third section, we try to give you some advice as to how to approach the tackling of real problem solving, and we give some general concepts involved in mathematical modeling. It must, though, again be stressed that we are all convinced that experience is the all-important ingredient needed for confidence in model formulation. If you have just read Sections I and 11 without making at least attempts at your own solutions to some of the problems set, you will not have gained any real experience in tackling real problems, and this section will not really be of much help. On the other hand, if you have taken the problem solving seriously in Section Ⅱ , you might find the general advice given here helpful.
Provided you have gained some confidence in tackling real problem solving in the earlier parts, you will be able to dabble with those problems in this section which appeal to you. Don’t feel you must work systematically through this section, but look for problems you want to solve--these are the ones that you will have most success in solving.
We hope that this book will at least point you in this direction. We are aware that this is not a finalized precise sort of text, but then using mathematics in practical problem solving is not a precise art. It is full of pitfalls arid difficulties; but don’t despair, you will find great excitement and satisfaction when you have had your first success at real problem solving!
A:Many books have been written on the topic of mathematical, modeling these years B:Books devoted to mathematical modeling usually pay special attention to modeling formulation C:The book introduced here does not claim that it had the best methods for teaching how to deal with real problems D:The book introduced here takes the mastery of model formulation as its main purpose
Text 4 Over the past few decades, there has been a considerable increase in the use of mathematical analysis, both for solving everyday problems and for theoretical developments of many disciplines. For example, economics, biology, geography and medicine have all seen a considerable increase in the use of quantitative techniques. Twenty years ago applied mathematics meant the application of mathematics to problems in mechanics and little else--now, applied mathematics, or as many people prefer to call it, applicable mathematics, could refer to the use of mathematics in many varied areas. The one unifying theme that these applications have is that of mathematical modeling, by which we mean the construction of a mathematical model to describe the situation under study. This process of changing a real life problem into a mathematical one is not at all easy, we hasten to add, although one of the overall aims of this book is to improve your ability as a mathematical modeler. There have been many books written during the past decade on the topic of mathematical modeling; all these books have been devoted to explaining and developing mathematical models, but very little space has been given to how to construct mathematical models, that is, how to take a real problem and convert it into a mathematical one. Although we appreciate that we might not yet have the best methods for teaching how to tackle real problems, we do at least regard this mastery of model formulation as a crucial step, and much of this book is devoted to attempting to make you more proficient in this process. Our basic concept is that applied mathematicians become better modelers through more and more experience of tackling real problems. So in order to get the most out of this book, we stress that you must make a positive effort to tackle the many problems posed before looking at the solutions we have given. To help you to gain confidence in the art of modeling we have divided the book into four distinct sections. In the first section we describe three different examples of how mathematical analysis has been used to solve practical problems. These are all true accounts of how mathematical analysis has helped to provide solutions. We are not expecting you to do much at this stage, except to read through the case studies carefully, paying particular attention to the way in which the problems have been tackled--the process of translating the problem into a mathematical one. The second section consists of a series of real problems, together with possible solutions and related problems. Each problem has a clear statement, and we very much encourage you to try to solve these problems in the first place without looking at the solutions we have given. The problems require for solution different levels of mathematics, and you might find you have not yet covered some of the mathematical topics required. In general we have tried to order them, so that the level of mathematics required in the solutions increase as you move through the problems. Remember that we are only giving our solutions and, particularly if you don’ t look at our solution, you might well have a completely different approach which might provide a better solution. Here, in the third section, we try to give you some advice as to how to approach the tackling of real problem solving, and we give some general concepts involved in mathematical modeling. It must, though, again be stressed that we are all convinced that experience is the all-important ingredient needed for confidence in model formulation. If you have just read Sections I and 11 without making at least attempts at your own solutions to some of the problems set, you will not have gained any real experience in tackling real problems, and this section will not really be of much help. On the other hand, if you have taken the problem solving seriously in Section Ⅱ , you might find the general advice given here helpful. Provided you have gained some confidence in tackling real problem solving in the earlier parts, you will be able to dabble with those problems in this section which appeal to you. Don’t feel you must work systematically through this section, but look for problems you want to solve--these are the ones that you will have most success in solving. We hope that this book will at least point you in this direction. We are aware that this is not a finalized precise sort of text, but then using mathematics in practical problem solving is not a precise art. It is full of pitfalls arid difficulties; but don’t despair, you will find great excitement and satisfaction when you have had your first success at real problem solving!
Which of the following statements in NOT true according to the second paragraph（）A:Many books have been written on the topic of mathematical, modeling these years B:Books devoted to mathematical modeling usually pay special attention to modeling formulation C:The book introduced here does not claim that it had the best methods for teaching how to deal with real problems D:The book introduced here takes the mastery of model formulation as its main purpose
Passage Two
When the TV viewer turns on his set, what sort of programs does he have to choose from You might think there would be more programs devoted to entertainment than to anything else, but that’s not the case. In most countries, fewer than 20% of broadcasting hours are devoted to entertainment. U. S. figures are high-34.8%, and the funlovig Canadians are even higher with 44%. Except Canada and Italy, all countries give more broadcasting time to education than to either information (news, documentaries and so on) or entertainment programs. Of course, few educational broadcasts take place during peak viewing times. In Japan though, more than 60% of broadcasting time is taken up with education of one kind of another-just another example of the businesslike Japanese philosophy. In the U. K. , the figure is 56.4%. The Italians have fewer educational programs than anyone else. They don’t go in for entertainment either. Only about ten percent of viewing time is devoted to dramas and serials, quiz shows, music, sports, etc. You will find more news information programs on Italian TV than anything else. That’s understandable in a country experiencing social and political changes. Italians rely on TV to tell them what’s going on-and events are happening almost too fast to follow. The percentage of time the U. S. devoted to news and documentary programs is much smaller. After education, most TV time is given to entertainment. Many of these programs are shown around the world
A:TV broadcasting hours devoted to education are more than those devoted to entertainment B:educational programs are shown during peak viewing times C:most of TV broadcasting hours are given to entertainment D:TV programs are shown for world audience to watch
Mr. Jackson devoted himself ______ teaching in the primary school.
A:to B:for C:by D:as
Based on this passage, the percentage of TV broadcasting hours devoted to education is greatest in ______.
A:Japan B:Italy C:Canada D:The United States
So far as the broadcasting hours devoted to entertainment are concerned, ______.
A:the Japanese figure is the highest in the figure B:the U. S. figure is smaller than the U. K. world C:the U. K. figure is second to the Japanese figure D:the Canadian figure is higher than that of any other country
下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。
{{B}}第一篇{{/B}}
| ? ? Many features similar to those
aeronautical innovations developed by man can be observed amongst birds, insects
and plants. At times, observations of these natural phenomena have inspired man
to imitate nature and modify existing designs. At other times, the natural
example has only been recognized well after great amounts of time and valuable
materials have been devoted to refining a similar human invention. ? ?Birds deserve credit not merely for demonstrating flight was possible, but for providing templates for the shape of aircraft wings. The wings of birds suggested the pattern for leadingedge wing slots that improve ascent at slow speeds and for conical cambered wingtips that increase lift and stability. Other characteristics of bird wings, such as a trailing edge flap to aid in smooth landings, were not recognized as important until they had been designed independently by aeronautical engineers. Considerable research effort in aeronautics could probably have been saved by more thorough analysis of bird flight. ? ?The insect world has also contributed significant ideas in the realms of navigation and guidance. In order to aid airline navigation during take-offs and landings under adverse weather conditions, engineers developed a system for locating the sun when it was hidden by clouds through observing polarized light—light which travels in a single direction. The research was instigated(鼓励,激发)after studies of honey bees demonstrated that they used this mechanism to determine their location when the sky was darkened. In another credit to the insect world, the evasive guidance systems of certain missiles use angular acceleration detectors modeled after the multi-lensed eyes of houseflies which amplify subtle movements by splitting images into a mosaic(马赛克)resembling a large display of televisions tuned to the same channel. ? ?Even entities which never take flight themselves are responsible for guiding the hand of aeronautical engineers. The winged seed of a palm tree was the model for an early glider, and the single-winged, autorotating maple seed was the prototype for a means of air-dropping cargo by parachute. |
A:more advanced products were used in airplanes B:more research was devoted to studying bird flight C:greater efforts were directed towards shape designs of aircraft wings D:greater emphasis was put on guidance systems
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