Explanatory writing takes "explanation" as the main form of expression and teaching scientific knowledge as the fundamental task, introducing things, clarifying things, and explaining the movement, change and development law of explanatory writing. Therefore, when reading this kind of article, it is natural to grasp the object of explanation and its characteristics and see how it is "said". For example, the article "Wonderful Cloning" in Unit 6 of Grade Two in junior high school may be read three times: First, grasp the outline-grasp the explanation points as a whole. The purpose of writing is to tell readers something or something. The knowledge conveyed by the author is the point of explanation, which is the central idea of plain text. So how to grasp it? There are three main methods: first, you can grasp the title of the article and make the main points clear. As the saying goes, "the title is the eye of the article", and the title of the explanatory text often reveals the center of the explanation. First look at the general title: "Wonderful Cloning", which shows that this is a knowledge introduction about magical cloning technology and reveals the secret of "cloning"; Looking at the content again, the full text uses four subheadings: what is cloning, cloning sheep "Dolly" before and after the birth of crucian carp, and cloning technology benefits mankind. Just browse the subtitle of the text and you will have a general understanding of the content of the text. Secondly, we can grasp the structure of the article and summarize the main points of explanation. General expositions tend to focus on a main issue or content, while some expositions need us to summarize the small explanatory points to form the explanatory points of the full text. For example, Wonderful Cloning uses a parallel structure to explain cloning from different aspects. In addition to the subheadings we mentioned earlier (or like some articles without subheadings), we can also summarize them according to the content structure of four parts. That is the significance, experiment, development and benefits of cloning. In addition, you can grasp the order of explanation and make the main points clear. Everything has its own order, and people know things according to a certain order, so sorting out the order of articles is helpful to clarify the center of explanation. For example, this passage mainly expounds things, and undoubtedly adopts a logical order: first write the meaning of cloning, then write the experiment of cloning, then write the development of cloning, and finally write the benefits of cloning to human beings and the thinking of cloning. The context of the writing is very clear, indicating that things are proceeding step by step, and the center of the article is clear at a glance. Second, reading intensive reading analysis-detailed discussion method If you want to explain things clearly and thoroughly, you must be inseparable from the interpretation method. Therefore, when reading expository articles, we should grasp the main methods of expository articles, and make clear the relationship and function of various methods of expository articles, so as to grasp the content and structure of expository articles more accurately. We might as well start from the following two aspects: first, we can extract the interpretation methods of each part from the full text. You might as well make a list and have a look. Second, we can grasp the key paragraphs and analyze the specific explanation methods. For example, in "What is cloning?" The author explains "cloning" in three ways: example, explanation and quotation. Examples: cite familiar examples from plants and animals to make difficult scientific knowledge easy to understand; Interpretation: trace the source of the word cloning and explain it; Quotations: The Journey to the West's story of pulling a handful of monkey hairs into a large group of monkeys vividly illustrates what cloning is all about and makes science and technology interesting. Third, reading taste-capturing the emotional points of chewing, like other styles, explanatory text also "speaks" the author's emotional attitude, which is indispensable for us to understand the text. Wonderful Cloning is a popular science article written by biologist Tan Jiazhen. To learn this text, we should not only understand the cloned scientific and technological achievements, but also learn the spirit of scientists' perseverance and constant climbing on the road of science, and have a preliminary understanding of science as a "double-edged sword". In order to explain what cloning is, the author carefully organized the materials and clearly introduced what cloning is, the development of cloning technology, the birth of Dolly the Sheep and how cloning technology benefits mankind. But the author is not limited to the general knowledge introduction, but incorporates his own appreciation and serious thinking. Specifically, this paper not only introduces us to the scientific knowledge of cloning, but also shows the "scientific spirit" including China scientists, and leads readers to look at the development of science and technology in an all-round way. When reading, we should find out the sentences that can express the rigorous, realistic and persistent attitude and spirit of scientists and appreciate them. For example: (1) "The cells of crucian carp in blastocyst stage were artificially cultured, and after 385 days and 59 generations of continuous subculture, the nucleus was sucked out of the cultured cells with a glass tube with a diameter of about 10 micron under a microscope." (2) "Only two of the189 nuclear exchange eggs hatched into fry, and finally only one young fish survived the difficulties. After more than 80 days of cultivation, it grew into a crucian carp with a body length of 8 cm." (3) "... take out the nuclei from the intestinal epithelial cells, liver cells and kidney cells of Xenopus tadpoles by superb surgery, and accurately put the nuclei of these cells into the eggs whose nuclei have been destroyed by ultraviolet rays. "(4)" After hundreds of gray, black and white operations, the white mouse finally gave birth to three little gray mice. " (5) "After 247 failures, they got a cloned ewe named Dolly in July 1996." (6) "... take out the nucleus from the egg cell with a very thin straw. ..... immediately injected into the enucleated "Scottish black-faced sheep" egg cells. ..... Then, the embryo is skillfully implanted into the uterus of another ewe. "(7)" It can be expected that many biologists, especially those engaged in asexual reproduction research, will seriously consider its significance and launch scientific discussions to educate people all over the world. " These sentences all embody the sacred "scientific spirit".