An element of a good article is that the author provides enough details to support the topic sentence of each paragraph. Expanding a paragraph is to use a set of such sentences to explain the central meaning of the paragraph. The following methods will help you fully expand the paragraph. Narration, description, examples and processes in these methods are often used to serve sentences. Narrative is developed in chronological order, which can be a paragraph, a few paragraphs or even the whole article. The main purpose of narrative is to tell readers a story, which has some connection with this article. Short stories are often used as examples. When you start a paragraph with a narrative, make the reader interested in the events and people in the events you describe. For example, this is my first day as a waiter in a busy new york restaurant. I am exhausted and finally finished. My hat is crooked, my apron is dirty and my feet hurt. The full tray I took felt heavier and heavier. I'm tired and discouraged, and I can't seem to do anything well. When I wrote a complicated check for a family with several children, the family had changed their ice cream order more than a dozen times, and I was ready to resign. Then my father smiled and handed me a tip. "Well done," he said. "You take good care of us." Suddenly, my fatigue disappeared. I smiled back. Later, when the manager asked me how I felt on my first day, I said, "Great!" " These few words of praise changed everything. The above account describes how tired he was at the end of his first day as a waitress, how he was praised by customers and gave up the idea of quitting his job, and the fatigue dissipated. B. when describing the author's writing, he often describes what he has seen and heard. Accurate and successful description enables us to see, hear, smell, taste and touch what is truly described. The following is a paragraph describing a walk on the Brooklyn Bridge. The author's description is very sophisticated. Even without crossing the bridge, you can imagine what the sidewalk looks like with this passage. On most traffic bridges, the only pedestrian passage is the sidewalk alongside the speeding vehicles. The pedestrian path here is a long corridor higher than the traffic; People can lean on the railing and watch the speeding cars below. The promenade is wide enough to place benches for pedestrians and cyclists. The old-fashioned Los Angeles police sentry reminds pedestrians that this is a boulevard after all. But the sidewalk is very narrow, and people walking can reach the big round cable wrapped in steel wire casing or the thick steel wire rope vertical to the suspender. Passing through the vertical structure is a set of diagonal steel cables-stay cables, which are connected somewhere below the road surface. C. give examples to illustrate that topic sentences are commonly used methods. Vivid examples will make readers better remember the content of topic sentences. The following article tells readers how insect control methods affect fish: In places with large forests, modern insect control methods threaten fish living in streams sheltered by trees. One of the most famous destruction cases in the United States occurred in 1955, which was the result of spraying in and around Yellowstone National Park. By that autumn, so many dead fish were found in the yellowstone river that athletes and the fish and wildlife managers in Montana began to be alert. About 90 miles of rivers are affected. On a 300-yard-long coastline, 600 dead fish were found, including brown trout, white fish and sucker fish. The natural food of trout-stream inlay has disappeared. D. Process If you have ever cooked a dish according to a recipe, you will know what it is like to unfold a paragraph according to the process. To start a paragraph with a process, we must first make clear the first step of doing something, and then describe these steps in detail with the help of transitional words such as first, second, third, …… next, then and finally. Look at the following example: once you meet someone who has stopped breathing, you should start artificial respiration immediately. First, let the patient lie on his back and use his fingers to remove foreign bodies from his mouth. Then tilt his head back so that his chin is up. Next, open his mouth, let his chin move forward, and hold his nostrils to prevent the air you blew into his mouth from escaping from his nose. Then put your mouth tightly over the victim's mouth and blow into his mouth until you see his chest bulge. Then turn your head to one side and listen to the exhaled airflow indicating air exchange. Repeat this process ... definition is also a means to expand the paragraph. In informative writing, readers can understand some concepts through the definition of terms; In persuasive writing, the author can establish a common language with readers through the definition of terms, which is the first step to persuade readers. Once a term is defined, you can make it clearer by giving examples, comparisons, analogies and descriptions. Look at this example: What exactly is genetic engineering? Genetic engineering is the name of the technology that scientists change or combine genes (genetic material) in organisms. Genes are a part of all living cells and carry chemical information that determines the characteristics of organisms; Genes are often called the "blueprint" of life. By changing the genes of organisms, scientists can manipulate the characteristics of organisms and their offspring. Finally, by manipulating genetic material, scientists hope to produce flowering organisms-microorganisms, plants and animals, which show higher productivity, lower cost and stronger disease resistance. At first, the data you collected may not matter. After careful observation, slowly, you find that some are similar. Then, you can classify these things according to a standard. The same group of things can be divided into different categories according to different standards, so when classifying, tell readers your standards. In the following example, the author divides new york into three situations in the first sentence, that is, the topic sentence, and then explains the classification criteria of these three situations in turn. There are roughly three new york. First of all, new york, a man or woman born here, takes this city for granted, and it is natural and inevitable to accept its scale and its turmoil. Second, the commuter's new york-the city is swallowed by locusts every day and spit out every night. Third, this is a new york with aspirations. Among the three trembling cities, the greatest is the last one-the final destination city and the target city. It is this third city that explains new york's highly nervous personality, its poetic behavior, its dedication to art and its unparalleled achievements. Commuters gave the city a tidal wave of agitation, locals gave it stability and continuity, but settlers gave it passion. G. Compare and discuss the similarities of people, places, objects, events or viewpoints, and compare and discuss them or their differences. When comparing or contrasting, we should follow certain standard points. For example, comparing computers and human brains, we can focus on two points: one is the density of information storage, and the other is the speed of information processing. In addition, the use of comparison and contrast to expand the paragraph is not only a simple list of similarities and differences, but also has a certain purpose. Or classify, or evaluate, or explain. In writing, there are two ways to compare and contrast: one is "alternating method", that is, compare or contrast one point in the commonness or difference of two things, then compare or contrast the next point, and so on. The other is the "block method", which provides all the information of one thing first, and then all the information of another thing. The following passage is carried out in accordance with the "alternating method" and compares the similarities and differences between computers and human brains. First of all, the author focuses on the information storage density to examine these two objects. Next, he compared the information processing speed of computer and human brain. How dense is the information stored in the brain? The typical information density of modern computers is about one million bits per cubic centimeter. This is the total information of a computer divided by its volume. As we have said, the human brain contains about 10 13 bits in a little more than 103 cubic centimeters, and for1013/103 =10/kloc. Therefore, the information density of the brain is 10 thousand times that of the computer, although the computer is much larger. In other words, the capacity of a modern computer that can process information in the human brain must be 10,000 times larger than that of the human brain. On the other hand, modern electronic computers can process information at the rate of 10 16 to10/7 bits per second, while the peak rate in the brain is ten billion times slower. The brain must be packaged and "wired" very cleverly. The total amount of information is so small and the processing speed is so slow that it can accomplish so many important tasks better than the best computer. H. Analogy Sometimes, in order to explain an abstract problem, or to convince readers, starting from a seemingly unrelated topic, the author finds the common ground between the two through comparison, thus drawing the conclusion that "A is like this, B is like this, so B is like this". This method is analogy. This method can not only make readers see the similarities between two unrelated things in poker, but also help readers understand abstract concepts and profound theories. In the following example, the author compares the learning process to the performance of a symphony orchestra, and the transitional language to with analogy indicates that the author is ready for analogy; After describing the performance of a symphony orchestra, the author reminds readers in a similar way; Next is analogy, which clearly explains to readers what the abstract process of learning looks like. Finally, we can use an elaborate symphony to describe learning, aiming at merging the familiar and new sounds. Symphony is a complex interaction between composers, conductors, musical instruments and various musical instruments, which develops synchronously towards the rich structure of themes. Some themes appear repeatedly, while others push the movement towards conclusions or solutions. Finally, each symphony has its own independent meaning, but it is also related to the previous and subsequent symphonies. Similarly, learning is a complex interaction among learners, teaching materials, available learning strategies and environment (including teachers). Skilled learners treat each task strategically to achieve the goal of constructing meaning. Some strategies focus on understanding the input information, some strategies try to link the meaning with previous predictions, and some strategies try to combine new information with previous knowledge. We know that the causal relationship between events is usually very complicated, so before writing, we should analyze it carefully to avoid oversimplification, especially to avoid giving readers the impression that there is one thing before and one thing after. In the following example, the author points out that the root cause of economic depression is an unhealthy economy. Instead of1the stock market crash in October 1929. The Great Depression was refined by the stock market crash in 1929 10, but the actual cause of the crash was an unhealthy economy. Although the ability of manufacturing industry to produce consumer goods has improved rapidly, the purchasing power of the public has remained relatively stable. Therefore, most workers, farmers and white-collar workers can't afford cars and refrigerators produced by factories because their income is too low. At the same time, the federal government has exacerbated this problem through economic policies that tend to encourage the rich to save excessively. Above, we discussed several common methods of developing paragraphs. Sometimes, only one method is used in a paragraph, but more often, several methods are used in the same paragraph. The following passage is an example. The author mainly expands the paragraph by giving details; The first sentence is a topic sentence, and the second, third and fourth sentences give details; At the same time, the author begins the paragraph by classification: the members of religious movements are divided into those who are in college, those who have dropped out of school, men, women, urban people and rural people.