第一段：总体描述图表，指明时间段，指出突出变化或不同
常用句型或短语：
As is clearly shown in the char/ table/graph, ___________
According to the figures given in the table/chart/graph, ____________
It can be seen from the table/chart/graph, _____________________.
The figures in the table/chart reflect that ________________.
especially, ________________（指出突出变化）
第二段：（分析原因）
There are several factors leading to this change / difference ……..
There are several reasons for _____________.(引出原因)
To begin with, _______(原因一)
In addition, ______________（原因二0
For example, _________（举例说明）
Last but not the least, __________（原因三）
To sum up——————————————（简要总结）
