以下是一些常用的英语四级作文万能句子，可以用于不同类型的作文中：

1. 引言句子：
- In recent years, the issue/problem of __ has been brought into focus.
- It is widely acknowledged that __ plays a significant role in our daily life.
- With the rapid development of __, the issue of __ has become increasingly important.

2. 论证句子：
- First and foremost, __.
- Another important factor to consider is __.
- Furthermore, it is worth mentioning that __.
- Moreover, __ can also contribute to __.

3. 举例句子：
- For instance, __.
- A good case in point is __.
- Take __ as an example, __.
- One classic example is __.

4. 结论句子：
- In conclusion, it is evident that __.
- From what has been discussed above, we can draw the conclusion that __.
- Therefore, it is high time that we took effective measures to __.

5. 建议句子：
- It is imperative that we should __.
- It is suggested that __.
- It is of great importance that __.
- We should make every effort to __.

6. 对比句子：
- On the one hand, __, but on the other hand, __.
- While it is true that __, it is also true that __.
- Although __, it is undeniable that __.

7. 引用句子：
- As the saying goes, "___".
- According to a famous philosopher, "___".
- In the words of __, "___".

这些句子可以帮助你在写作时更加流畅地表达观点和论证，但需要根据具体的作文题目和内容进行适当的调整和修改。另外，多背诵一些经典范文和高分作文，可以帮助丰富自己的表达方式和提高写作水平。