大学英语六级205及答案解析.doc

1、大学英语六级 205及答案解析(总分：448.03，做题时间：132 分钟)一、Part I Writing (3(总题数：1，分数：30.00)1.For this part, you are allowed thirty minutes to write an open letter to the major of the city based on the following situation: You should write at least 150 words, and base your composition on the outline given below: 1近年来，

2、本市的空气污染情况越来越严重； 2你认为造成空气污染的主要污染源是哪些?应该采取哪些措施? 3呼吁所有市民积极行动起来，治理空气污染。 （分数：30.00）_二、Part II Reading C(总题数：1，分数：71.00)Programming languages are how people talk to computers. The computer would be just as happy speaking any language that was unambiguous. The reason we have high level languages is because

3、 people cant deal with machine language. The point of programming languages is to prevent our poor frail human brains from being overwhelmed by a mass of detail. Architects know that some kinds of design problems are more personal than others. One of the cleanest, most abstract design problems is de

4、signing bridges. There your job is largely a matter of spanning a given distance with the least material. The other end of the spectrum is designing chairs. Chair designers have to spend their time thinking about human bodies. Software varies in the same way. Designing algorithms (运算法则) for routing

5、data through a network is a nice, abstract problem, like designing bridges. Whereas designing programming languages is like designing chairs: its all about dealing with human weaknesses. Most of us hate to acknowledge this. Designing systems of great mathematical elegance sounds a lot more appealing

6、 to most of us than pandering to human weaknesses. And there is a role for mathematical elegance: some kinds of elegance make programs easier to understand. But elegance is not an end in itself. And when 1 say languages have to be designed to suit human weaknesses, I dont mean that languages have to

7、 be designed for bad programmers. In fact I think you ought to design for the best programmers, but even the best programmers have limitations. I dont think anyone would like programming in a language where all the variables were the letter x with integer subscripts. If you look at the history of pr

8、ogramming languages, a lot of the best ones were languages designed for their own authors to use, and a lot of the worst ones were designed for other people to use. When languages are designed for other people, its always a specific group of other people: people not as smart as the language designer

9、. So you get a language that talks down to you. Cobol (计算机通用语言) is the most extreme case, but a lot of languages are pervaded by this spirit. It has nothing to do with how abstract the language is. C is pretty low-level, but it was designed for its authors to use, and thats why hackers like it. The

10、argument for designing languages for bad programmers is that there are more bad programmers than good programmers. That may be so. But those few good programmers write a disproportionately large percentage of the software. Im interested in the question, how do you design a language that the very bes

11、t hackers will like? I happen to think this is identical to the question, how do you design a good programming language? Give the Programmer as Much Control as Possible. Many languages (especially the ones designed for other people) have the attitude of a governess: they try to prevent you from doin

12、g things that they think arent good for you. I like the opposite approach: give the programmer as much control as you can. When I first learned Lisp (表处理语言), what I liked most about it was that it considered me an equal partner. In the other languages I had learned up till then, there was the langua

13、ge and there was my program, written in the language, and the two were very separate. But in Lisp the functions and macros I wrote were just like those that made up the language itself. I could rewrite the language if I wanted. It had the same appeal as open-source software. Aim for Brevity. Brevity

14、 is underestimated and even scorned. But if you look into the hearts of hackers, youll see that they really love it. How many times have you heard hackers speak fondly of how in, say, APL, they could do amazing things with just a couple lines of code? I think anything that really smart people really

15、 love is worth paying attention to. I think almost anything you can do to make programs shorter is good. There should be lots of library functions; anything that can be implicit should be; the syntax (句法) should be simple; even the names of things should be short. And its not only programs that shou

16、ld be short. The manual should be thin as well. A good part of manuals (说明书) is taken up with clarifications and reservations and warnings and special cases. If you force yourself to shorten the manual, in the best case you do it by fixing the things in the language that required so much explanation

17、. Admit What Hacking Is. A lot of people wish that hacking was mathematics, or at least something like a natural science. I think hacking is more like architecture. Architecture is related to physics, in the sense that architects have to design buildings that dont fall down, but the actual goal of a

18、rchitects is to make great buildings, not to make discoveries about statistics. What hackers like to do is make great programs. And I think, at least in our own minds, we have to remember that its an admirable thing to write great programs, even when this work doesnt translate easily into the conven

19、tional intellectual currency of research papers. Intellectually, it is just as worthwhile to design a language programmers will love as it is to design a horrible one that embodies some idea you can publish a paper about. How to Organize Big Libraries? Libraries are becoming an increasingly importan

20、t component of programming languages. Theyre also getting bigger, and this can be dangerous. If it takes longer to find the library function that will do what you want than it would take to write it yourself, then all that code is doing nothing but make your manual thick. So I think we will have to

21、work on ways to organize libraries. The ideal would be to design them so that the programmer could guess what library call would do the right thing. Are People Really Scared of Prefix Syntax? This is an open problem in the sense that I have wondered about it for years and still dont know the answer.

22、 Prefix syntax seems perfectly natural to me, except possibly for math. But it could be that a lot of Lisps unpopularity is simply due to having an unfamiliar syntax. Whether to do anything about it, if it is true, is another question. What Do You Need for Server (服务器)-Based Software? I think a lot

23、of the most exciting new applications that get written in the next twenty years will be Web-based applications, meaning programs that sit on the server and talk to you through a Web browser. And to write these kinds of programs we may need some new things. One thing well need is support for the new

24、way that server-based applications get released. Instead of having one or two big releases a year, like desktop software, server-based applications get released as a series of small changes. You may have as many as five or ten releases a day. And as a rule everyone will always use the latest version

25、. You know how you can design programs to be debug gable (调试器)? Well, server-based software likewise has to be designed to be changeable. You have to be able to change it easily, or at least to know what is a small change and what is a momentous one. Another thing that might turn out to be useful fo

26、r server based software, surprisingly, is continuations. In Web-based software you can use something like continuation-passing style to get the effect of subroutines in the inherently stateless world of a Web session. Maybe it would be worthwhile having actual continuations, if it was not too expens

27、ive. What New Abstractions Are Left to Discover? Im not sure how reasonable a hope this is, but one thing I would really love to do, personally, is discover a new abstraction something that would make as much of a difference as having first class functions or recursion or even keyword parameters. Th

28、is may be an impossible dream. These things dont get discovered that often. But I am always looking for. （分数：71.00）(1).Designing algorithms (运算法则) for routing data through a network and designing bridges are both nice, abstract problems.（分数：7.10）A.YB.NC.NG(2).Since languages have to be designed to s

29、uit human weaknesses, it has to be designed for bad programmers.（分数：7.10）A.YB.NC.NG(3).Architecture is related to physics, so the actual goal of architects is to make discoveries about statistics.（分数：7.10）A.YB.NC.NG(4).Libraries are getting bigger and this can be dangerous for programming languages.

30、（分数：7.10）A.YB.NC.NG(5).The point of programming languages is to prevent our poor frail human brains from_.（分数：7.10）_(6).The argument for designing languages for bad programmers is that_.（分数：7.10）_(7).When I first learned Lisp, what I liked most about it was that it considered me（分数：7.10）_(8).Hackers

31、 could do amazing things in APL with just_.（分数：7.10）_(9).If you force yourself to shorten the manual, in the best case you do it by _that required so much explanation.（分数：7.10）_(10).Web-based applications are programs that sit_ and talk to you through a Web browser.（分数：7.10）_三、Listening Comprehens(总

32、题数：1，分数：15.00)A.One student received a higher grade than he did.B.He will have to take a number of exams later.C.The test is more difficult than he expected.D.Several students in his class have received top grade.A.Take a break.B.Go to work.C.Do the other problems.D.Keep trying.A.They are too many a

33、nd she cant read them all.B.They are too boring to read.C.She feels too tired to read any books.D.They are too heavy for her to carry.A.Clean air.B.Friendly folks.C.Freshness.D.Peaceful surroundings.A.He doesnt think it necessary to refuel the car.B.He can manage to get the gasoline they need.C.He h

34、opes the woman will help him select a fuel.D.He thinks it is difficult to get fuel for the car.A.They think cinemas are too far away from their home.B.They are disappointed with the films produced these days.C.They both dislike films about adventure stories.D.They both like the idea of going to the

35、cinema at night.A.The application should be well-written.B.The application should have been sent as soon as possible.C.The application will certainly bring him great profit.D.The application can help him get that good job.A.Its not important how he dances.B.Its too crowded to dance anyway.C.If hes c

36、areful, no one will notice.D.No one knows the steps to the dance.四、Section A(总题数：2，分数：10.00)A.Places the man has visited.B.A paper the woman is writing for a class.C.School activities they enjoy.D.The womans plans for the summer.A.She has never been to Gettysburg.B.She took a political science cours

37、e.C.Her family still goes on vacation together.D.Shes interested in the United States Civil War.A.Why her parents wanted to go to Gettysburg.B.Why her familys vacation plans changed ten years ago.C.Where her family went for a vacation ten years ago.D.When her family went on their last vacation.A.Its

38、 far from where she lives.B.Her family went there without her.C.She doesnt know a lot about it.D.Shes excited about going there.A.American literature.B.Elementary education.C.Art history.D.Experimental medicine.A.They are professional storytellers.B.They are the parents of young children.C.The stori

39、es will help them improve their vocabulary.D.The stories are required for a course.A.It uses an extensive vocabulary.B.Friends of the speakers.C.The same person.D.Fictional characters.A.At the beginning of a semester.B.During midterm week.C.At the end of a semester.D.In the middle of summer vacation

40、.五、Section B(总题数：3，分数：30.00)A.The color of the dog.B.The price of the dog.C.Whether the dog will fit the environment.D.Whether the dog will get along with the other pets in the house.A.It must be trained so it wont bite.B.It needs more love and care.C.It demands more food and space.D.It must be look

41、ed after carefully.A.They are less likely to run away.B.Its easier for their masters to train them.C.They are less likely to be shy with human beings.D.Its easier for them to form a relationship with their masters.A.Because there are no signs to direct them.B.Because no tour guides are available.C.B

42、ecause all the buildings in the city look alike.D.Because the university is everywhere in the city.A.They set their own exams.B.They select their own students.C.They award their own degrees.D.They organize their own laboratory work.A.Most of them have a long history.B.Many of them are specialized li

43、braries.C.They house more books than any other university library.D.They each have a copy of every book published in Britain.A.Very few of them are engaged in research.B.They were not awarded degree until 1948.C.They have outnumbered male students.D.They were not treated equally until 1881.A.The dis

44、advantages of working in an office.B.The waste produced in an office.C.To save resources when working in an office.D.How to save water in a restroom.A.2.B.3.C.4.D.5.A.Using computers is a waste of resource.B.Many people dont turn off the computers after using them.C.Computers are run by electricity.

45、D.A computer is not a must for working.A.We are short of paper.B.The printing is not important.C.We should save paper.D.We have to pay for the paper.六、Section C(总题数：1，分数：10.00)How many of you drink cola? Nearly everybody. Did you know that cola started out not as a soft drink but as a (36) 1for head

46、ache back in the late 1800 s ? John S. Pamberton, a druggist from Atlanta, had (37) 2 for many months trying to find a for the common headache. He worked in his backyard, mixture and heating different combination of oils and (38) 3until he found one that seems promising. Pamberton (39) 4the mixture

47、and began selling it in drugstores as a (40). 5syrup that the customer had to mix with water before drinking. Colas (41) 6from a syrup to a carbonated soft drink came about quite by accident. One day, a customer came into a drugstore (42) 7of a headache and asked for (43) 8 cola syrup. He wanted to take it right away. So he asked the clerk to mix the medicine while he waited. The clerk, instead of walking to the other end of the counter to get (44) 9, suggested