4.3语篇的逻辑方法-1

1.按照时间的先后顺序进行描述

例

In the relatively short span of sixty years, there has been an incredible evolution in the size and capabilities of computers. Today, computer chips smaller than the tip of your fingernail have the same capabilities as the room -sized machines of years ago. The first computers were developed around 1945. They were so large that they required special air- -conditioned rooms. About twenty years later, in the 1960s, desk- -sized computers were developed. This represented a gigantic advance. Before the end of that same decade, however, a third generation of computers, which used simple integrated circuits and which were even smaller and faster, had appeared. In 1971, the first microprocessor, less than one square centimeter in size, was developed. Today, modern microprocessors contain as many as 10 million transistors, and the number of transistors and the computational speed of microprocessors doubles every eighteen months.

2.根据观念逻辑进行划分

• 从一般到具体，即由总类到分类
• 由具体到一般，即由分类到总类

例

Living aboard a space station in orbit around the Earth for months at . time poses problems for astronauts' bodies as well as for their minds. One major problem is maintaining astronauts physical health. Medical treatment may be days or even weeks away, as there may not be a doctor on board. Illnesses such as appendicitis or ulcers, routinely treated on Earth, could be fatal in space because of the delay in getting to a doctor. Furthermore, surgery may be impossible because blood would float around inside the operating room. Another health problem is the potential for bone deterioration. In a weightless environment , the body produces less calcium. Astronauts must exercise at least three hours a day to prevent bone loss. A second major problem is maintaining astronauts' mental health. Being confined for long periods of time in dark and hostile space undoubtedly produces anxiety. Loneliness and boredom are other psychological concerns. Finally, how can astronauts "let off steam" interpersonal conflicts develop?It is clear that space station duty will require off steam astronauts who are not only physically but also mentally strong.

3.比较对照法

将同类的事物按照某种特定的规则进行比较分析，是一种常用的方法。

• 在同一角度下逐步的把人或事的相同点或不同点交替的表现出来的方法。

• 当作者想深入的讨论两种人或事物的相似点，或者这些相似点的内涵又比较复杂，需要进行解释时，可以先阐述一人或事物的各种特点，然后再同另一人或者事物进行全面比较，这就是整体对比法。

例

If you are planning to buy a personal computer, you should know some of the basic similarities and differences between PCs and Macs. First of all, both PCS and Macs are composed of the same elements: CPU, the electronic circuitry to run the computer memory (hard and/or floppy disk drives) for storing information; input devices such as a keyboard or mouse for putting information into the computer; and output devices such as a monitor, printer, and audio speakers for conveying information. They also have the same uses: PCs are used to communicate on computer networks, to write (with the help of word processing and desktop publishing software), to track finances, and to play games. Macs are likewise used to communicate, write, calculate, and entertain.(逐个比较相同点)

There are some differences, however. Whereas you will find more PCs in business offices, you will find more Macs in classroom. Although Macs are the computers of choice of people who do a lot of art and graphic design in their work, PCs seem to be the choice of people who do a lot of number crunching". Finally, there is a difference in the availability of software, vendors, and service for the two computers. 6In general, there is a lot of PC-compatible software, but relatively little Mac software. 6Furthermore for a Mac, you must purchase your machine and get service from Macintosh- authorized dealer, whereas many different computer stores sell and service PCs.(整体比较)

构建比较关系

构建对照关系