考研英语作文中常用的句型包括：
表示原因
There are several reasons why...
The main/primary reason for...
A major factor/cause/reason contributing to...
It is/these are due to a variety of factors, such as...
The root of the problem/issue/phenomenon can be traced back to...
The cause of X is not limited to one factor, but also involves...
表示影响
This has a profound/significant/positive/negative impact on...
X has far-reaching/consequential effects on...
It brings about/draws attention to...
常用句型套路
Although it is commonly held that..., it is unlikely to be true that...
It is true that..., but this is not to say that...
It would be possible to think that..., but it would be absurd to claim that...
There is absolutely no reason for us to believe...
结构句型
There be结构
It结构
递进式结构
主语从句结构
表达建议
Here are some suggestions I’d like to put forward...
To express my sincere gratitude to you...
I’m sending this email to...
Thank you for your time and consideration.
表达对比
Never before in history has the issue of...been more evident than now.
There has been a trend in recent years towards...
Quite obviously, immediate action is needed to...
表达争议
There is a public controversy nowadays over the issue of...
Those who criticize...
On the other hand, people who favor...
举例说明
Two examples that aptly illustrate this point involve the fields of...
A telling example of...
Positive example: One compelling argument in favor of...
Negative example: It might be tempting to...
以上句型可以帮助你构建考研英语作文的基本框架，使文章结构清晰，表达准确。