Paragraph对于英文论文来说是非常重要，甚至有人会说Paragraph是整篇英文论文的缩影。大家如果想写好英文论文的话，那么每一个Paragraph都需要深思熟虑再下笔。下面就主题句和中心思想这两个方面用例子跟大家讨论下如何写好Paragraph。
主题句与推展句
01
主题句
如何写好主题句（topic sentence）是表达段落主题句子。它用以概括段落大意，要求全段其他文字都围绕它展开。请看下例： My mother has passed along to me certain rules for getting along with others. Don’t argue with parents；they will think you don’t love them. Don’t argue with children；they will think themselves victimized. Don’t argue with spouses；they will think you are a tiresome mate. Don’t argue with strangers；they will think you are not friendly. My mother’s rules，in fact，can be summed up in two words：Don’t argue. 主题句中提出“certain rules”是指什么？展开句中通过四个“Don’t argue ——”逐一加以交代。从结构来看，这是一个比较典型段落，它包括了主题句，推展句和结论句（即本段中末句）。 （1）主题句位置 主题句通常放在段落开端，其特点是开门见山地摆出问题，然后加以详细说明。其作用是使文章结构更清晰，更具说服力，便于读者迅速地把握主题和想象全段内容。主题句可以放在段中起到承上启下作用，或放在段尾起概括全段作用。但初学者比较难于掌握，因而在四级考试中，考生应尽量采用将主题句放在段落开头写作手法。 例1：Our life today depends very much on energy. In towns and in villages，on farms and in factories，machines have made life easier than it used to be. The machines use energy，and energy is needed for heating，lighting，communications，carrying goods —— everything. Factories and industrial plants use a great deal of energy to make the things that we use and buy and sell. 这段文字所讲主要是能源问题。第一句就概括性地提出“我们目前生活很大程度上依赖于能源”。而随后出现三句都是具体事例，对第一句进行说明和论述。我们可以断定第一句为该段主题句。 例2：（主题句）No one can avoid being influenced by advertisements.（推展句1）Much as we may pride ourselves on our good taste，we are no longer free to choose the things we want，for advertising exerts a subtle influence on us.（推展句2）In their efforts to persuade us to buy this or that product，advertisers have made a close study of human nature and have classified all our little weakness. 以上这段由三句话组成。第一句是主题句，直截了当指出无人不受广告影响这个主题，接着列举两个推展句对其补充和支持，指出我们已无法自由选择所需商品，理由是广告商已仔细研究了我们心理，并完全掌握了我们弱点。句子衔接自然，步步紧扣主题。 （2）如何写好主题句中关键词 段落主题句对主题限定主要是通过句中关键词来表现。关键词要尽量写得具体些。对“具体”要求包括两个方面：一是要具体到能控制和限制段落发展；二是要具体到能说明段落发展方法。准确地把握关键词是清楚地表达段落主题、写好段落主题句重要前提之一。在上面例1，例2中，主题句关键词分别为：depends very much on energy；no one can avoid being influenced. 我们再看下列例句： 原句1：He can fix a bicycle himself. 斜体部分应为主题句中关键词。但它只是限制了段落发展部分内容，并没有告诉读者该用哪种方法展开，是用因果关系法还是用分类法？ 修正：He can fix a bicycle himself in several simple steps. 修正：There are several reasons why he can fix a bicycle himself. 原句2：She tries to improve her looks. 斜体部分应为主题句中关键词。她试着改变她面容理由是什么？或者她采取什么方法来改善呢？我们无法从关键词中清楚得知。 修正：She tries many ways to improve her looks. 修正：There are some reasons why she tries to improve her looks. （3）如何写好主题句中心思想 主题句由两部分组成，即主题（topic）和中心思想（controlling idea）。中心思想作用是导向（control）和制约（limit）。我们前面谈到关键词就反映了中心思想。所谓导向就是规定段落发展脉络，所谓制约就是限制主题覆盖范围，两者不可分割。没有导向，内容就会离题或偏题；没有制约，内容就可能超出一个段落所能容纳范围。对于初学写作人来说，“导向”重要性容易理解，但如果由他们自己来构思一个主题句，就可能忽视“制约”这一面。例如： There are two ways in which one can own a book. The first is the property right you establish by paying for it，just as you have made it a part of yourself and the best way to make yourself a part of it is by writing in it. 本段主题句如果没有in which引出定语从句，那么two ways不仅不能起制约作用，而且也不能起导向作用，句子本身读起来也就使人觉得欠缺点什么。 Exercise is beneficial to your heart. A 22-year study was conducted by doctors in California. They found that people who work at physical jobs experience fewer heart attacks than other people. These active people work all the time at moderate speeds，their daily routine gives them an adequate amount of exercise and helps them stay in shape. “Exercise is beneficial”这是毫无疑义。但主题句中如不加上“to your heart”来加以control 和limit，那就流于空泛。因此，紧紧把握主题句中controlling idea导向和制约作用，是短文写作成功关键之一。02
推展句
（1）主要推展句 主要推展句（major supporting statement）主要特点是：围绕段落主题句展开每一个推展句本身都不要求作进一步说明或证明，句与句之间关系是相互独立又是互相连接。 例1：（主题句）There are several factors affecting climate.（推展句1）One factor is the mount of sunlight received.（推展句2）Altitude，or the height above sea level，also determines climate. （推展句3）The oceans have an effect on the climate of adjacent land.（推展句4）In addition，climate is influenced by the general circulation of the atmosphere. 主题句指出影响气候几个因素。然后用四个扩展句说明四种因素。第一种是太阳光接收量，第二种是海拔高度，第三句和第四句分别是海洋和大气环流因素。 （2）次要推展句 次要推展句（minor supporting statement）是指对主要推展句作进一步事实分析和举例说明。它从属于某一个或某几个推展句。 例2：（主题句）I don’t teach because teaching is easy for me.（主要推展句1）Teaching is the most difficult of the various ways I have attempted to earn my living：mechanic，carpenter，writer.（主要推展句2）For me，teaching is a red-eye，sweaty-palm，sinking-stomach profession.（次要推展句1）Red-eye，because I never feel ready to teach no matter how late I stay up preparing.（次要推展句2）Sweaty-palm，because I’m always nervous before I enter the classroom，sure that I will be found out for the fool that I am.（次要推展句3）Sinking-stomach，because I leave the classroom an hour later convinced that I was even more boring than usual. 从属于主要推展句2三个次要推展句起着解释说明作用，分别解释red-eye，sweaty-palm，sinking-stomach含义，这就更加形象生动地证明了“teaching is not easy”这个主题。 （3）主要推展句与次要推展句关系 主要推展句与次要推展句关系（relation）基本可以遵循下面“三部分”（three-part）规则。 1）、每个主要推展句都应该是对主题句中表示主要思想关键词直接、明确说明。 2）、每个次要推展句都应该说明它主要推展句。 3）、含有讨论说明或分析问题通常既要有主要推展素材，又要有次要推展素材。 （4）写好推展句方法 主题句及关键词确定后，开始选择和主题有关信息和素材。实质上，针对关键词测试每一个所选择素材就是一个分类过程。有一种常用方法就是句子展开前加以设问，然后解答，即设问－解答（why-because）方法。下面我们通过举例来看一看这种分类过程是如何完成。例3：假设（suppose）Topic sentence：English is an international language？设问（why）Why can we say English is an international language？ 解答（because）Because：English is spoken by pilots and airport control operators on all the airways of the world. Because：Over 70 percent of the world’s mail is written in English. Because：More than 60 percent of the world’s radio programs are in English. Because：Pakistan was once one of the British colonies. Because：Many members of the International Language Society are selected from English-spoken countries. 从上面可以看出，最初三个推展句是和关键词an international language一致。第四句和主题句不统一，尽管第四句会成为另一主题句（Many Pakistanis speak English）很好推展句。第五句说服力不强。 以上就是关于Paragraph的写作讲解，同学们在写英文论文的时候一定要注意段落的处理，做到环环相扣,如有不懂的可以私聊小编哦！