【正文】 any countries. Nowadays, Many countries set up English for science and technology, not only in research centers of English for science and technology, but in English majors in universities to study English for science and technology and develop talent of this field. Although English for science and technology is similar to mon English in appearance, which are both posed with phoics, vocabulary and grammar, as it extends its applying areas, there is more and more necessity of English for science and technology in world‘s policy, economy and science and technology. Key words: EST。 words。然而，由于其獨特的形式，在語言長期發(fā)展的過程中，它有大量的其他語言不具備的特性。 雖然科技英語在外表上和普通的英語沒多大差別，都是由語法，詞匯語音等組成，它在應(yīng)用領(lǐng)域也有了很大的擴展，科技英語在世界經(jīng)濟政治科學和技術(shù)方面也有了越來越大的必要性。也不經(jīng)常運用比喻、排比、夸張等修辭手段，而是要準確表達客觀規(guī)律，按邏輯思維清晰地描述問題。在科技英語中也有一些省 略倒裝和分離現(xiàn)象，條件從句的使用，還有祈使語句在一些說明書中的使用是經(jīng)常出現(xiàn)的。 科技英語詞匯具有國際性。 在語法結(jié)構(gòu)上，科技英語大量使用被動語態(tài)。在科技文章中，同一詞語詞義的中文摘要 多專業(yè)化，即同一個英語常用詞不僅被多個專業(yè)采用，而且含義也各不相同，區(qū)別很大。科技英語更多的是敘述普遍真理、描述特性、功能或過程及交代推理或假設(shè)等 ,因此它具有自己獨特的語言特點和規(guī)律 :清晰、準確、精練、嚴密、正式和客觀。 第五章對文章進行了總結(jié)，得出了結(jié)論，也就是科技英語總的特點。the classification sentence type ,for example, triangles can be divided into three kinds according to the three degree of angle .The first kind is the acute triangles whose three angles are acute .The second one is the obtuse triangles whose only one angle is an obtuse angle .The third one is the right triangles whose only one angle is a right angle. Another one is the auxiliary statements that refers to the sentences , which are assisted in the main statements in order to further illustrate or support the main statements. The main statements and the auxiliary statements in place is tandem relations. For example: Si Nan was posed of two parts : a spoon and a tray . The spoon was cut from an intact piece of natural loadstone, with its handle as the south pole and its round , smooth bottom as the center of gravity. The tray ,on the other hand, was made of bronze, and at the center ,there was a round ,smooth groove ,carved with checks and words indicating the 24 directions. This passage, the first sentence is the main statement, the following two sentences are auxiliary statements, to further explain to support the first statement. Finally ,the conclusive statements are the results of technical personnel reasoning and analytic thinking, and sometimes are summed up to the discovery of scientific and technological personnel .In these sentences, inferences must be concise and clear and have a certain depth and breadth of research .For example, the theory of sphereheavens(渾天說 ) played an important part in the history of Chinese astronomy, 福建師范大學碩士論文 2 exerting significant influence on the design and manufacture of ancient astronomic instruments, as well as on the explanation of relevant astronomic theories. Plenty of studies have shown that the conclusive statements usually appear at the end of the article. Frequent Use of Long Sentences In EST , authors often use long sentences to convey plicated thoughts and logic connections as a functional style. In the English stylistic feature, function attached to the structure. According to the statistics by foreign researchers, the average sentence length is, respectively ,22 , (using word as the unit) in Popular Mechanics, Science Digest, American Science. We can clearly find out that ST English tends to use long sentences, in the most condition, the stronger the academic literature is, the longer the sentences are. argues that, the short sentence is less than 15 words in English for science and technology is not very often to be seen .The sentences in English for science and technology, pared to everyday English and literary English, are more plicated and much longer. Because in EST, the sentences are accurately, objectively, logically structured and conceptually strong. In general, it is appropriate for science and technology workers who are accustomed to reading or specialize in science and technology more and more long sentences are used in EST. In EST stylistics, long sentences often consists of a subject with a number of clauses, the clause with the phrase, mutually dependent and constrained so there exists a plex phenomenon in EST articles that a long sentence often includes another one. Plenty of studies appear that long sentences using in EST stylistics are divided into three kinds of structure: the simple sentence, the plex sentence and parallelism sentence. First of all, in short ,plex sentences is a bination of the main clause and subordinate clause. On the one hand, in EST ,the sentences have much higher demand on the degree of accuracy and precision, on the other hand, pound sentences can not only enhance logic of a sentence but can shorten the length of the sentence. So plex sentences can not be avoided frequent using in EST stylistics. The author will elaborate on the frequent using of plex sentences in scientific English stylistics in the following section. This section, the author mainly analyzes the simple sentence and the parallelism sentence structures in the application of EST stylistics. 1 .Simple sentences. A simple sentence is defined as those sentences that have but one subjectpredicate structure, which constitutes the main part of one sentence. The authors, in this structure of this long sentence in EST ,tend to utilize a lot of adjectives, noun phrases, prepositional phrases, nonfinite forms of verbs and so on to modify the sentence. In the following the author uses an article as an example to illustrates the application of simple sentence： ―We use touch screens everywhere: tourist kiosks, automatic teller machines, pointofsale terminals, industrial controls. Half a dozen vendors, plus inhouse departments at major manufacturers, produced $800 million worth in 2020. The market is growing because the interfaces are easy