Exercise 6. Choose the right variant.
1. I don't recall having seen you before. Are you sure we (meet)?
2. Sally earns a lot of money; her new job is much (good) paid than the old one.
3. We went to (a, the, -) Gladiator to see a new film because we (read) very good reviews. Next Saturday we (go) to Hyde Park, if it (not, rain).
4. I watched a documentary on TV last night. It was all about the problems (threatening, threatened) the environment. I (shock) to find out how little I (know) about globe warming or acid rains.
5. Nature delicately (balance) and the extinction of one species (may, must, should) have a serious effect on (other, others, the others).
6. It is the fault of mankind that so many species (endanger), so it's our responsibility to protect those while we still can.
7. (Famous) sporting event in the world, the Olympic Games, began in Greece in 776 BC.
8. Medieval sports were not as organized as events in ancient times: at fairs or festivals men (would, were used to) lift heavy stones and women (would, be used to) run races.
9. I'm sure he is not aware (at, in, of) the harm he (do) for us.
10. The old lady (could, was able to, must) identify the robber who (attack) her the previous day.
11. I'm sure that in this time of technology advances, we (find) already some way to solve the world's ecological problems.
12. Many people feel (happy) when they are with friends than when they are on their own.
13. Certain sports teams (support) by fans all over the world and individual athletes (see) as celebrities.
14. During the 18th and 19th centuries national organizations were formed which made sure that the rules (follow) and arranged regular sport competitions.
15. When I was a child, I (used to, was used to) love my dad's stories about Africa. He (work) there for many years before I was born.
16. This dish (make) (from, at, on) a recipe given to me by my grandfather who was (a, an, the, -) excellent cook.
17. My idea of an ideal holiday (change) a lot in the past few years. Nowadays, I'd much rather go away in spring when (most, most of, more) places (not, fill) with tourists.
18. 1 have just spoken to three women, (neither, none, either) of (whom, who, them) speaks Spanish.
19. We (invite) some friends for dinner tonight. Would you like to join (to, at, in, -) us?
20. She has been waiting for him for ten years already. If she (not, love) him, she (not, wait) so long.
WRITING
Projects. Perform the project given
Many companies have a Web site that provides information on their products and services. Use a search engine to locate a company in your career field. Suppose you are a recruiter for that company and you’ll be attending a series of college career fairs. Create a one-page information flyer that you can hand out to prospective recruits. It should include: company’s name, location(s) URL; a brief description of the company’s mission, products, and services; a description of typical working conditions; instructions on how to submit a resume electronically.
UNIT 13
PROGRAMMING LANGUAGES
Answer the questions. Then discuss in pairs.
1) How long have you been using the computer?
2) Can you program on your computer? What do you need to make programs?
3) What programming languages have you already known? Which ones are you studying at the moment?
Vocabulary Bank Unit 13
Task 1. Read, write the translation and learn the basic vocabulary terms:
1. abstraction
2. addition
3. arbitrary text files
4. assembly code
5. assembly languages
6. asset management
7. binary values
8. built-in
9. compiler
10. concerned
11. concurrency
12. convenient
13. debugged
14. deficiency
15. designate
16. discretion
17. ease-to-use
18. encapsulation
19. encourage
20. establish
21. evolve
22. executable file
23. execution
24. extension language
25. facilitate
26. full-fledged application
27. garbage
28. heir
29. high-level languages
30. human-like words
31. implement
32. in order to run
33. inherent cross-platform
34. interpreter
35. low-level languages
36. mnemonic
37. natural languages
38. notation
39. object code
40. object-oriented programming
41. permanently
42. problem-oriented languages
43. procedural languages
44. query languages
45. realm
46. robust
47. source code
48. specificity
49. standpoint
50. statement
51. to hide
52. to interface
53. to join
54. usability
TEXT 13A. TYPES OF PROGRAMMING LANGUAGES
Programming languages are classified as first-, second-, third-, fourth-, or fifth- generation languages, according to when they were developed and how sophisticated they are. The first- and second-generation languages are very difficult to use and are considered low-level languages. The others are sometimes called high-level languages.
Machine Languages
Machine languages are the first generation of programming languages; these languages consist of instructions the computer is actually built to execute. Since at the hardware level computers understand only binary notation (1s and 0s), programming with a machine language requires writing out the binary values of the program instructions. A simple machine-language command might be 10101001 10101010 1011101011010100." Machine languages vary from one model of computer to another, as each model of processor is built differently. Machine languages are difficult to understand and use, so they are rarely used directly by programmers today. Since the computer understands only machine language, however, any program written in any other language must be translated into machine language in order to run.
Assembly Languages
Assembly languages are the second-generation programming languages and first to use alphanumeric symbols to write code. The creation of assembly languages depended on the development, using machine language, of an assembler. An assembler is a program that translates the assembly code into machine language. It is necessary to have one assembler for each kind of assembly language and for each kind of computer used.
Assembly languages are the simplest improvement over machine language; their commands are simple mnemonic codes that stand for the binary instructions of machine code. When programmers need to deal with the computer directly, they use assembly language; because it is so close to the hardware level, it is possible to write very efficient programs in assembly language. That same closeness to the hardware level, however is what makes assembly language difficult to use for large programming projects. Therefore, most assembly programming today is used for writing small modules that can be included in larger programs written in more convenient languages.
Procedural Languages
Procedural languages are the third-generation languages. They are also called high-level languages because they represent a higher level of abstraction from machine code than do assembly languages. Procedural languages employ more human-like words, and each has its own set of syntax rules. They are also more efficient, allowing the programmer to express with one statement what would take several commands in machine language. They are called procedural languages because they allow the programmer to create procedures that implement structured programming. Procedural languages are by far the most widely used programming languages.
The development of procedural languages was started by the invention of translation programs that could convert the syntax of the high-level language to machine code that the computer could execute. These translators are compilers and interpreters.
A compiler converts an entire program written in a high-level language to machine language, storing it in what is called executable file, to be run later at the user's discretion. The original code is then called the source code, and the machine-language code is called the object code.
An interpreter reads each high-level program statement, then translates it to machine language and instructs the computer to execute the statement immediately. It creates no object code and no executable file; from the programmer's or user's standpoint, the computer executes the original code. This method of execution gives the programmer more immediate control of the machine and lends itself to an interactive method of programming and refining code and testing it immediately. The interpreter program does not permanently change the code, allowing users or programmers to make additions and other modifications to the program more easily. However, interpreting the code takes more processing than running a compiled program, so interpreted programs generally run slower than compiled programs.
Some of the most frequently used procedural languages include the following: BASIC, PASCAL.
Problem -Oriented Languages
Fourth -generation languages, the problem-oriented languages, are a mixed bag of strategies to make programming easier. They were created to solve specific user and programming problems rather than to achieve the broad general usability of procedural languages. This group of languages includes object-oriented languages, application generators, authoring systems, HyperTalk, and query languages.
Object-Oriented Programming.
Object-oriented programming (OOP) takes a different approach to creating applications. Traditional programming treats data and instructions as separate items with the instructions controlling the data; the instructions are active controls on passive data. In object-oriented programming, an object is created by joining data and instructions in a process known as encapsulation. Once an object is made and debugged, it will work. Objects can then be linked together with messages (calls to the object to implement its instructions on its data) to form full-fledged applications.
Query languages.
Query languages are used specifically within the realm of databases. These languages are designed to instruct the computer to retrieve and manipulate database information and can be used to develop specific applications based on databases, such as database publishing and project management.
Natural languages
The fifth and final generation of programming languages does not involve the generation of any code. These natural languages use the normal grammar of the spoken language to create programs. Some natural programming languages include Intellect, Broker, and Explorer. Although they don't yet meet, heir inventors' ideal, they are showing promise, and continued advances in this area may someday radically change the way we use computers and how we create programs.
Дата добавления: 2018-10-26; просмотров: 681; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!