A.主题句呈现的形式
1）文首开门见山， 提出主题， 随之用细节来解释， 支撑或发展主题句所表达的主题思想。 最常见的演绎法写作方式。
例1.The panda is a popular animal. Stories about the panda in the Washington Zoo are always front page news and important features on television newscasts. Stuffed pandas are among the most popular toys for children, and panda postcards are always in demand in zoo gift shops.
例2.Today the problem of environment has become more and more serious. The world population is rising, so quickly that the world has become too crowded. We are using up our natural resources too quickly and at the same time we are polluting our environment with dangerous chemicals. If we continue to do this, human life on earth will not survive.
2）文尾，在表述细节后， 归纳要点， 印象， 结论建议或结果， 以概括主题。 这是英语中最常见的归纳法写作方式
例3.A human body appears to be rather soft and delicate, compared with that of a wild animal, but it is actually surprisingly strong. In deed, its very softness and looseness is an advantage; it makes man good at moving about movement of all living things of his own size, because he can do so many different things with his limbs. Man’s games show how he can control his own body. No other land creature can swim as skillfully as man; more has such varied grace; very few lives as long as he; none is so strong in its natural resistance to disease. Therefore man has a great advantage in his battle against the risks of damage and death that threaten him.
3）文中，通常前面只提出问题， 文中的主题由随之陈述的细节或合乎逻辑的引申在文中导出， 而后又作进一步的解释， 支撑或发展。
例4. Nothing is as useful as a flashlight in a dark night if a tire goes flat. Few inventions are so helpful to a child who is afraid of the dark. In fact, the modern flashlight brings light to many dark situations. Finding something in the back of a closet is easy with a flashlight in hand a camper also needs one after the light of the campfire has been out.
4）。首尾呼应，为突出主题， 作者先提出主题， 结尾时再次点出主题， 这种首尾呼应的写作方式较为多见。 但前后表述主题的句子不是简单的重复， 后面的表述往往有进一步的引申或发展的意味。
例5.（首段）Shu Pulong has helped at least 1000 people bitten by snakes, “ It was seeing people with snakes bites that led me to the career.“she said…
（尾段）“The sad story touched me so much that I decided to devote myself to helping people bitten by snakes.” Shu said.
5）无主题句，即主题句隐含在全文中， 没有明确的主题句。 必须根据文篇中所提供的事实细节，进行全面考虑，综合分析，然后找出共同的东西，归纳成一般概念。必须注意的是，既不能以偏概全，也不能在概括时过于宽泛，要恰如其分。
例6.Joshua Bingham studied 4 years at the University of Paris and decided to leave his graduation. He transferred to the
Q: What is the main idea of the passage? ＿＿＿＿
A. How Joshua Bingham became a lawyer.
B. Bingham is a diligent student.
C. Joshua Bingham received an excellent education.
D. A good lawyer needs good education.
[分析]此文没有主题句。全篇共四句，只陈述了四个细节（detail）性的事实。因此就答案本身看，个个都对。读者只能将所有的details综合起来，进行逻辑推理，才能构成一个没有言明的主题思想（unstated main idea）。
由于文中主要涉及了Joshua Bingham接受教育的情况，即作者想告诉我们的是：Joshua Bingham接受过良好的教育，所以答案是 C
除了以上主题句呈现的常见形式外还要注意标志词
文章或段落的主题句常常会出现在一些标志性的提示后。如：on the whole, as a result, in short, therefore, thus……I agree with the opinion that…；Given all these points above, I would support the idea that…； For all the reasons mentioned above, I would prefer…