写段落的方法 (三)
(6) 因果关系法（Cause and Effect）：
这方法是以因与果构成一段落，顾名思义，文句必须分析事件或陈述句的因果关系，而逻辑性的理据占最重要，但要说清楚却不容易，原因是一个"因"可以引来很多后果，而一个"果"也可能来自很多原因，所以在撰写时，必先考虑那些因或果最有说明力。
I) 由因到果（From Causes to Effect）：
Example 1:
A lack of exercise is one of the major factors contributing to obesity（过度肥胖）. When we eat, we consume energy(measured as calories). When we exercise, we expend energy or burn up calories. For example, when we run for an hour, we burn up approximately 450 calories, depending on our body size. When the number of calories we consume exceeds the number we burn up, the excess energy is stored in the body in the form of fat. If a person is inactive, it is more likely that he will not burn up all the calories consumed, so obesity can result.
本段思路清晰，说明引致过度肥胖的其中一个原因是缺少运动，并以跑步为例，指出运动可以燃烧热量（卡路里），若果一个人缺少运动，便无法把进食所吸收的热量去除。当然，如果这是一篇文章，作者还可写出其它引致肥胖的原因，如：过度进食（Overeating），遗传影响（Hereditary influences），以及新陈代谢缓慢（Slow metabolic rate）等。
Example 2:
Cigarette smoke contains nicotine（尼古丁）, several cancer producing or irritating substances, and carbon monoxide gas（一氧化碳气）. Damage to the lining of the bronchial tubes（支气管） is much more common among cigarette smokers than non-smokers, even when there is no obvious disease. Some of these changes are considered to be pre-cancerous. Lung function is generally reduced among cigarette smokers. Cigarette smoking is a greater danger than other factors － such as community air pollution － in the causation of lung cancer and chronic bronchitis（慢性支气管炎）
本段说明吸烟带来许多后果，同上一段近似，用吸烟与不吸烟者作出比较，更加强主题的说服力。
II) 由果及因（From Effect back to Cause）：
We all know the story "Dong Shi blindly imitated Xi Shi"(东施效颦). Dong Shi, an ugly woman, heard that Xi Shi was as beautiful as a fairy. One day she went to see for herself. however, Xi Shi happened to be sick that day with stomachache. She knitted her eyebrows and wore a painful expression, yet she was still surprisingly beautiful. Dong Shi mistakenly thought that her beauty derived form the painful expression on her face. Therefore Dong Shi knitted her eyebrows in imitation of Xi Shi. Of course, she looked even uglier. The story shows us that in the pursuit of beauty we must bear in mind that truth, only truth, is beautiful. Anything artificial or false is ugly.
本段从表面看，是由故事的铺写到寓意，而实质上，寓意是因，而故事则是果。
写作技巧：
在撰写因果关系的段落或文章时，可从以下几种方向思考：
1) Multiple Causes →Effect
就以上述过度肥胖症为例：
形成过度肥胖症的原因有很多种，有些人因为缺少运动，有些人因为遗传，有些更可能是社会或环境因素，所以，当你要写此题目时，必须对每种成因作出解释，才能有说服力，你可以用facts, examples, data, case study等来支持自己的论点。
Example: Outline for an essay:
2) Cause →Multiple Effects
某些题目是说明陈述句的影响，即一个"因"可引致很多"果"，我们要从多角度去看题目，才能全面兼顾，而且要清楚说明因果两者的关系，例如：
3) The Causal Chain 连锁因果关系
连锁关系意指一个果引来一个因及另一个果，如是者，因果相连。
例如：一个超重的吸烟者有呼吸问题，如何改善此情况呢？
Exercise:
Below is a set of effects that are given in no particular order. Decide which of the effects are immediate and which are remote. Then organize them into an outline for an essay. Choose one of effects to develop a paragraph.
The Effects of Watching Television:
1. People get fat.
2. There are more divorces.
3. More people get eyestrain.
4. There is more violent crime in our cities.
5. People are lonely.
6. People are more afraid of each other.
7. People do not like reading anymore.
