下面是30天沖刺英語四級寫作之議論文精講(3)，希望考生能深入理解英語四級議論文寫作要點。
　　Smoking is a bad habit that does a lot of harm to human health. Cigarette smoking does great harm to human health. In many cases, cigarette has proved to be the direct cause of such a fatal disease as cancer-hence its nickname, "Cancer Stick". Experts say that smoking one cigarette can reduce one’s life by about 15 minutes and that chain smoking is far more hazardous. Recent findings of medical research show that even a tiny drop of nicotine (about 3 grams in weight) can kill a large animal like a horse. Some medical reports have also proved that heavy smoking would seriously affect an adult’s sexuality, and smoking after a meal also disturbs one’s digestive system. Cigarette smoking not only jeopardizes the physical health of a smoker, it also affects the health of a nonsmoker who passively inhales the polluted air into his or her lungs when he or she is exposed to a winding shroud of cigarette smoke. The impact on such passive smokers (also called second-hand smokers), according to the experts in the medical field, can be even more damaging, and that is why smoking is usually prohibited in most public places. (196 words)
　　(2)議論文中常用的詞句與短語
　　一.數據對比用語：
　　1. … are similar in their range of indicators
　　2. …cause / lead to a rapid / slow increase / decrease in the number / amount of…
　　3. …cause …to drop…
　　4. …climb dramatically from…to…
　　5. …constitutes about…percent …
　　6. …continue to rise / fall…
　　7. …continue to widen / shorten…
　　8. …declines to less than …percent.
　　9. …drop / fall to as many / much / little as…
　　10. …fall / rise / increase / decrease dramatically
　　11. …fluctuates between…
　　12. …grow only marginally from…to…
　　13. …increase / decrease slowly
　　14. …increase/ decrease lightly
　　15. …is doubled
　　16. …is inversely proportional to…
　　17. …is significantly lower / higher than…
　　18. …lead to an increased number / amount of…
　　19. …level off / remain constant at…
　　20. …lower the percentage of …
　　21. …maintain approximately the same number of…
　　22. …narrow down to…