在英语说明文和议论文中，单篇文章分析事物的原因比较常见，也是命题作文中的一种重要题型。这类题目作文要求考生对社会现象或社会问题进行解释，摆出原因。
基本结构如下：
P1: S1 Problem (general)
S2 Problem (specific)
P2: S3 Thesis
S4 Cause 1
S5 Detail 1/Detail
S6 Detail2/Cause2
S7 Cause 2/Detail
S8 Detail 1/Cause3
S9 Detail 2/Detail
P3: S10 Conclusion
句型如下：
S1: In the last few years/ recent years, there has been /China has experienced a dramatic increase/ growing tendency in the number of PCs/ the crime rate.
S2: According to a recent/new survey/ study/ research in 1998, the number/ percentage of students who…/ teenage smoking has almost doubled/tripled/ increased/jumped from 5% to 8%/ Decreased/dropped by 5% as against/ compared with last year/ 10 years ago
S3: A number of/ Several factors/ causes might contribute to/ lead to/ account for the sudden rise/ phenomenon/ problem
S4: Part of the explanations for it/ One of the most common factors/ causes is that…
S5:
S6: … is also responsible for the problem./ Another contributing factor/cause is…
S7:
S8: Perhaps/ But the primary/ fundamental factor/ cause is that…
S9
S10: We might do more than identify the caused/factors; it is important to take action to…
The significance of … is far-reaching; it might exerts a profound influence on…
Models:
Why College Students Take a Part-time Job
1． 最近几年越来越多的大学生加入打工的队伍
2． 为什么大学生打工
3． 大学生打工的意义
(1)According to a recent survey, about 56 percent of Chinese college students held a part-time or temporary job in 2000, compared with nearly zero in 1990, and this figure may increases to 70 percent this year. (2)College students are working as tutors, salespersons, engineers and doing whatever work they can find.
(3)Why do they want odd jobs—jobs usually requiring little skill and knowledge? (4)The primary reason, I think, is money. (5)Feeling the financial pressure as books, movies and bus fares have all gone up in price, there is scarcely a young boy or girl who does not want to earn a little money to help cover the increasingly higher college costs, and at best save enough to traveling or buy things they have long desired. (6)In this way they hope to be financially independent and avoid the indignity of having to ask for money again and again. (7)Besides they want to gain some experience in the ways of society. (8)Students growing up from nursery school to college with realities. (9)Working on a part-time basis can provide them with a rare opportunity to know the outside world and prepare them for a future career.
(10)The significance of college students doing a part-time job means more than money and experience: It will broaden their outlook and exert a profound influence on their personality and life.
Children’s Schoolbags Are Getting Heavier
1. 现在学生背上的书包越来越重
2. 学生学业负担减轻不了的原因
3. 结论
(1)These days we often hear our children groaning under the pressure of an ever-increasing burden of their studies. (2)The schoolbags on their back are getting heavier and heavier, and the hours spent on their assignments longer and longer
(3)Why can’t their burden be relieved in spite of social protest? (4)For one thing, parents have a strong desire for the early intellectual achievement of their children. (5)They believe that if you don’t force them to read more, a golden opportunity for success will be lost and the chances of their being admitted to key schools, and then to colleges will be slim. (6)So children are under constant pressure to score high, test well, aim first. (7)For another, our teachers ally themselves with parents in applying pressure. (8)Since scores are not only the mark of success or failure for a particular students, but also a measurement of a teacher’s performance, it is natural for a teacher to assign more homework for his own sake as well as for his students. (9)Failure to produce students who win first place in school academic examinations is often seen as evidence of bad teaching.
(10)To lighten children’s academic burden is not easy, but is worth trying, for after all parents and teachers don’t want the heavy schoolbags to crush their children.
Teenager Smoking Soars
1. 描述近些年来青少年吸烟人数的变化
2. 分析造成这种情况的主要原因
3. 提出一些建议
(1)In the past 20 years China has experienced an alarming increase in teenage smoking: the number of boys who smoked rose from 6 percent in 1980 to 23 percent in 2000, and during the same years, the number of girls who smoked increased as much as 15 times. (2)The statistics look quite disturbing and cause people to ask why.
(3)The factors for a great rise in teenage smoking are complex. (4)Some attribute it to the increased standard of living which enables kids to have more pocket money, and others place the blame on cigarette advertising and the import of cigarettes, which give them easy access to Marlboros. (5)Whatever the causes, only particular external circumstances have been examined. (6)The factors, actually, are psychological as well as social. (7)Most young people begin to smoke just out of curiosity: they have a strong desire to experience the pleasure of smoking which is forbidden to them. (8)They also have a subconscious feeling that smoking will make them mature and tough and sophisticated. (9)When they light up a cigarette, and produce puffs of smoke carelessly, they are under the illusion that they are growns-up instead of kids and that they are admired rather than rejected by society.
(10)To help them get rid of such foolish ideas is the first step towards the effort to prevent children from starting to smoke, and then we may conduct a more extensive campaign to make them aware of the dreadful consequences of taking up the habit.
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