托福写作如何达到英语母语者水平 托福考试

　　There were, however, no US calls for the overthrow of successive Colombian governments. On the contrary,the US supported the Colombians with armaments, finance and goodwill.
　　By contrast则用于两者的对比，比如：Rory is always on time for work.By contrast,Vicki is always late. 这里by contrast不能写成on the contrary
　　（2）on the one hand…on the other hand
　　On the one hand…on the other hand用于陈述两个相反的观点，而不是两个并列的观点（You use on the one hand to introduce the first of two contrasting points, facts, or ways of looking at something.），比如：
　　On the one hand,if the body doesn't have enough cholesterol, we would not be able to survive. On the other hand,if the body has too much cholesterol, the excess begins to line the arteries.
　　语义承接可能是学生比较陌生的一种衔接手段，但它非常重要。事实上，雅思考试在关于衔接部分的满分评分标准中就有这么一条：uses cohesion in such a way that it attracts no attention要做到衔接自然，光靠连接词还不够，还要使用语义承接。
　　语义承接是指通过上下文之间的承接关系来自然行文，比如通过指示代词、人称代词等对前一句中出现过的内容进行指代，或者对前一句话中出现的关键词进行转述，解释，从而形成自然的承接关系。语义承接现象在地道英文中很常见，举个新概念英语3的例子：
　　(1) Recent developments in astronomy have made it possible to detect planets in our own Milky Way and in other galaxies.

      (2) Thisis a major achievement because, in relative terms, planets are very small and do not emit light. (3) Finding planets is proving hard enough, but finding life on them will prove infinitely more difficult. (4) The first question to answer is whether a planet can actually support life. (5) In our own solar system, for example, Venus is far too hot and Mars is far too cold to support life. (6) Only the Earth provides ideal conditions, and evenhere it has taken more than four billion years for plant and animal life to evolve.
　　第二句开头用This来指代首句的内容，这是一种很常见的句间衔接方式，我们平时在写作中可以多加应用。第三句开头作者用finding planets is proving hard enough来对第二句的内容做承接，接着用连接词but进行转折，说明在外行星上发现生命的难度。接下来第四句对第三句进行解释说明。第五句作者使用for example对第四句的内容进行举例。第六句开头Only the Earth provides ideal conditions呼应了第五句的内容Venus is far too hot and Mars is far too cold to support life，然后作者用and even here…进一步强调了生命产生的难度之高。
　　可以看到，开头几个句子环环相扣，逻辑非常严谨，而且作者使用了指示词以及名词等形式对句子进行衔接，读起来非常自然。平时在阅读中我们可以多留意句子与句子之间的语义承接现象，并在写作中多模仿，这样才能不断提高句子的衔接和连贯性。