星期二、如何写说明原因段和说明方法段
一、段落基本句型构造
1.说明原因段
说明原因段一般出现在图表阐释类和说明现象类作文的第二段，其基本句型构造是：先用一句话引出下文对现象或问题原因的说明，这是段落的主题句；然后用3-5句话列举2-3点具体的原因，以支持主题句。
例
Directions : For this part , you are allowed 30 minutes
to write a essay entitled What Electives to Choose . You should write at least
120 words following the outline given below in Chinese
:
1.各大学开设了各种各样的选修课。
2.学生因为各种原因选择了不同的选修课。
3.以你自己为例……
第二段：说明原因段
(1) There are many different factors deciding
what electives the students choose . (2) Among all these factors , the interest
of the students plays a very important role . (3) The students , of courses ,
would like to learn what he or she is interested in . (4) Moreover , many
students will consider whether they could learn some practical skill by the
elective , because nowadays companies are placing emphasis on a candidate's
practical skills . (5) Besides , the ability and the prestige of the teacher is
also an important factor influencing the student's choice .
2.说明方法段
说明方法段一般出现在方法对策类作文的第二段（偶尔也会出现在第三段，具体根据提纲），其基本的句型构造是：先用一句话引出下文对解决办法、应对措施或决定因素的说明，这是段落的主题句；然后用3-4句话列举2-3点具体的方法、措施或决定因素，以支持主题句；最后再用一句话对前面的方法做出总结（这句话有时可省略）
例
Directions : For this part , you are allowed 30 minutes
to write a composition on the topic Reduce Waste on Campus . You should write at
least 120 words following the outline given below in Chinese
:
1.目前有些校园内浪费现象严重。
2.浪费的危害。
3.从我做起，杜绝浪费。
第三段：说明方法段
(1) Considering the seriousness of the problem
, it is an urgent thing for us to take effective measures to eliminate waste on
campus . (2) Firstly , we college students must stop wasting water , electricity
and food in our daily life . (3) Secondly , we should learn to be economical and
try to avoed spending money on something useless . (4) Thirdly , we have
responsibility to call on all our schoolmates to fight against waste . (5) Only
in this way can waste on campus be eliminated in the near future
.
来源：原版英语网
