Everyone lives by selling something. For example, teachers live by selling knowledge, philosophers by selling wisdom and priests by selling spiritual comfort. Though it may be possible to measure the value of material goods in terms of money, it is extremely difficult to calculate the true value of services which people perform for us. The conditions of society are such that skills have to be paid for in the same way that goods are paid for at a shop. Everyone has something to sell.

　　由此可见，好的主题句能帮助作者阐明观点，起到提纲挈领的作用。作者围绕段落的中心论点，运用多种方法展开论证，达到以理服人的效果。

　　三)、用好连接词和过渡句

　　从行文需要出发选用恰当的连接词、过渡句可使整篇文章文句流畅，句意转换自然，同时使表达合乎逻辑，文章结构严谨。倘若一篇议论文的段落里不乏高级词汇和复杂语法结构，但缺少了连接词、过渡句的润色而不能从一个观点自然地过渡到另一个观点，或段落里的各论据(supporting sentence)连接松散，势必削弱论证的效果，就算不上一篇好的议论文。下面分别说明如何有效运用连接词与过渡句。

　　1、句与句的连接词

　　连接词通常由连词、副词、介词短语和插入语等充当。如何有效使用连接词，使句意连贯、紧凑，以体现文章良好的严密的论证逻辑?

　　2.段与段的过渡句

　　过渡句帮助作者展示文章的条理和层次。恰当运用过渡句能使表达锦上添花。当文章从一个层次转换到另一个层次，或由一段内容转入另一段内容时需要用过渡句。恰当有效的运用过渡句，效果明显(见下文，题目及要求略，黑体部分为过渡句)。

　　Wearing school uniform every day spreads an order over many schools. Is it good or bad for students? Different people, however, have different opinions on this matter.

　　Some people say that it has a bad effect on developing students’ personal character. According to them, students are tired of wearing the same clothes every day, which is hard to tell who’s who. Furthermore, the cost of the school uniform is not low as many people think. With the bad quality, it’s not well worth the money.

　　However, as a popular saying goes: “Every coin has two sides.” Others argue that it is good for students. In their opinion, wearing school uniform will prevent students from wasting so much money on clothes and the time on catching up with the fashion. In addition, it’s easy for the teachers to recognize the students. There is no doubt that wearing school uniform every day is good for students.

　　In short, I firmly support the view that we should wear school uniform.(康珍，2005)

　　上文黑体部分综合体现了恰当、有效运用连接词和过渡句的最佳效果。全文行文流畅、衔接自然、条理清楚，浑然不觉作者是在套用各种连接词和过渡句。因此，非常有必要熟记一些常用典型的议论文过渡句，使议论文结构严谨，论点清楚，行文流畅。

　　1)引言段的常用过渡句

　　Recently we had a heated discussion on…, Opinions are various among different people.

　　Different people have different opinions on the question of …

　　They differ greatly in their attitudes towards …

　　Different people hold different views/opinions on this matter.

　　Although most people think… I believe…

　　此类过渡句能迅速引起读者注意，自然而然地引出全文要讨论的话题，或者开门见山地阐明文章的论点。

　　2)主体段的常用过渡句

　　Some may hold the view that… because… But others have a negative attitude. From their point of view…

　　Some people think that… While others believe…

　　Some people are for the idea of… because… But some people are against the idea of… because …

　　本文所指议论文的主体段可以是一段也可以是两段。通过正确使用过渡句，文章思路清晰，结构清楚，显示作者严谨思维，增强表达效果。

　　3)结论段的常用过渡句

　　As far as I am concerned, I totally agree with the statement that…

　　Therefore, it’s easy to draw the conclusion that…

　　As a consequence/result, I firmly support the view that…

　　Taking all these factors into consideration, we may reach the conclusion that…

　　To sum up/in a word/in conclusion/in short/above all/in general/ generally speaking, I still hold the view that…