第一单元曾提到，段落由三个部分组成，最后一部分就是结论句（the concluding sentence）。结论句通常与主题句一样包含有段落的中心思想，然而所用措辞与主题句不同。
在示范段落1-1，主题句是：We all know that cigarette smoking is a dangerous habit because it causes health problems.
结论句是：It is clearly identified as one of the chief causes of death in our society.
例如在关于“cigarette smoking”的示范段落1-1中，中心思想是“the health problems caused by cigarette smoking，关键词是”health problems“。
在上述示范段落中，隐含的问题是“What are the health problems caused by cigarette smoking？”结论句作出的回答是It is identified as one of the chief cause of death in our society.
在上述段落中，主题句的关键词是“health problems”，而在结论句中，关键词是“causes of death”。
Our neighborhood has been greatly changed.When I last visited there，about half the homes had been torn down to make way for a superhighway.The remaining buildings were plastered with billboards and surrounded by traffic signs and litter.Now the whole neighborhood has become dirty，noisy and full of cars.
主题句：Our neighborhood has been changed.
主题句隐含的问题：“How has the neighborhood changed？
细节：1.a superhighway built—noisy and full of cars
2.full of billboards，traffic signs and litter—dirty
结论句：Now the whole neighborhood has become dirty，noisy andfull of cars.
结论句关键词：dirty，noisy and full of cars