如何解决托福写作词汇不足问题?

　　针对这个问题，我选自两篇习作：
　　学生作文之一 30分钟
　　someone said that teachers not no longer useful, nevertheless I don’t agree it。
　　Now, computers are widely in all kinds of fields. And it is more and more important. But some of special fields computers can’t do any thing. For example, whe the child was young. They come to school. They can’t use any machine before. They need a warm hand from mother techer more than cold computer key. So I don’t agree it。
　　这是一名中国考生在30分钟内写的“文章”—— 其实，根本不是文章。错误百出，时态混乱，动词错误，逻辑关系不明等等错误。
　　学生作文之二 30分钟
　　Compared to the automobile or train, the bicycle nowadays tends to be more common as a transport. Some people are think that the bicycle is the best way to tour. I am of the opinion that riding bicycle has advantage and disadvantages。
　　To begin with, bicycle is the cheapest transport. In china, people just need spend RMB 400 to buy a high quality bicycle. The car, however, at least is spent RMB 40000. To many Chinese people, they prefer to buy a bicycle because they have no enough money to buy a car. Next, sometimes riding bicycle is more convenient than driving a car. For example, I have to spend 1 hour to drive car cover 10 miles during the rush hour from my home to my office in Beijing. At same distance, I only need 20 minutes by riding bicycle. Finally, I think the bicycle do not make heavy pollution to our environment。
　　这些文字是在中国考生中非常有代表性的。其他教师和考生可以阅读类似的作文，然后进行批改训练。提高自己的写作教学和写作能力。
　　根据这些情况，我在NATIONAL GEOGRAPHY 杂志上选取了部分含有考生需要的句型，首先进行分析，然后让学生模仿。看看下面选取的一段文字：
　　The wolves play an integral part in the ecosystem in the archipelago, and their diet can offer scientists important clues about the dynamics between predator and prey。
　　Investigating the feces of the elusive wolves, Darimont found that their diets consist to a large extent of black-tailed deer. But he also found that their diets vary greatly depending on location. On the outer islands, for example, wolves are far less likely to have a deer for lunch than on the inner islands。
　　These findings suggest that wolves can deplete resources in isolated areas, making the link between the predators and their prey more delicate there。
　　The information is important for understanding not only island ecosystems, but also for conservation efforts. If scientists can understand how species behave on isolated islands, they may be able to figure out how the species will behave in other places that are becoming more fragmented。
　　选自：Canada"s Rain Forest Wolves a Link to Past
　　Stefan Lovgren October 1, 2004
　　从这段文字中，我首先教学生学习：
　　ecosystem
　　biota
　　biodiversity
　　play an integral part in
　　play a key role in
　　offer somebody something
　　dynamics between …and…
　　predators and prey
　　然后根据第二个段落，讲解现在分词短语结构，
　　consist of consist to a large extent of
　　depend on depend to a large extent on
　　比较结构的对称性和倒装性
　　be likely to do something
　　not only…but also…
　　然后指导学生学习写作：分析下面一篇学生作文：
　　Living in the big cities, people are more likely to forget the key roles that animals play in an ecosystem. But almost all animals can do good, directly or indirectly, to our life. For example, fish and shrimp offer not only foods but also scientific research materials. Birds in various colors and shapes offer scientists new clues to understand the dynamic between human and other animals. From this point of view, animals must be well protected。
　　这是一个学生的写作。对比前后两篇作文，明显看到进步。
　　如果我只是单纯地讲解单词，学生不可那写出这样的文章。但是，我给学生讲解的完整的句子和句子之间的逻辑关系。就直接启发学生的思维，导致分数的提高。 从这个教学实例可以推出，教学生提高句子量，应该是写作突破的方法之一。