在Tackle之后，被Tackle球员已下行为不正确的是（）。

A:只要是即刻做，可将球朝任意方向释放球 B:放开球后，不起来而只是远离球 C:倒地后立刻将球传出给队友 D:在达阵线前倒地时前伸压球触地达阵

Tackle中下列说法正确的是（）。

A:擒捉持球员的球员都是行Tackle球员 B:每个Tackle都有被Tackle球员而不一定有行Tackle球员 C:被Tackle球员在卧倒在地上或坐在地上后才算倒地 D:执行Tackle球员必须马上站立

Tackle中，下列说法错误的是（）。

A:执行Tackle者必须在倒地后马上放开持球球员 B:如果敌方企图操弄球，被Tackle球员必须马上放开球 C:操弄球球的球员必须双脚站立 D:如果被Tackle后进入极阵区，球员可达阵得分

Tackle中，对于参与Tackle的球员以外的球员，下列说法错误的是（）。

A:在持球球员将球放开后可单膝跪地操弄球 B:Tackle成立后，持球球员放开球后，双脚站立的球员只能从球后方，及双方倒地球员较近阵线方向来操控球 C:除被Tackle外，任何占有球的球员不能在Tackle处旁倒地 D:球员不许阻止被Tackle球员传球

在Tackle中，以下说法正确的是（）。

A:站立的球员不可阻止对方球员接近球 B:球员可阻止被Tackle球员站起或离去 C:躺在地上的球员可Tackle占有球的球员 D:在达阵线外被Tackle球员不可尝试持球碰达阵线

英式橄榄球比赛中，球在地上，而非tackle时，以下情况允许的是（）。

A:持球球员立刻持球站起来 B:倒在地上的球员Tackle对方 C:持球球员传球或放开球，马上离开 D:站立球员倒越躺在地上持球或附近有球的球员

英式橄榄球比赛中，Tackle中以下行为中允许的是（）。

A:Tackler在放开对方球员后立刻操弄球 B:Tackler立刻站起或远离球 C:被Tackle球员在倒地后阻挡对方拿球 D:球进入极阵内，任何球员都可压球触底

tackle之后适用规则14。

tackle之后出现下列哪一种行为，裁判员会判罚踢？（）

A:被tackle球员继续持球 B:被tackle球员朝敌队阵线的方向释放球 C:被tackle球员朝自己阵线的方向推球行 D:tackler球员立即离开tackle

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:to become a good mathematical modeler B:to tackle as many mathematical problems as possible C:to do the problems given in the book on one's own D:to have confidence in constructing mathematical models