四级作文是大学英语四级考试中的重要部分，作文的开头和结尾都是非常关键的部分，因此需要灵活运用万能句型来提高文笔的效果。下面是一些常用的四级作文开头结尾模板万能句型，供大家参考：

1. 开头万能句型：

- In recent years, with the rapid development of...

- Nowadays, people are becoming increasingly aware of the importance of...

- It is widely acknowledged that...

- As the saying goes, '...'

- With the advent of...

- In today's society, there is a growing trend towards...

- It is a common phenomenon that...

- There is no denying the fact that...

- It is a well-known fact that...

2. 结尾万能句型：

- In conclusion, it can be said that...

- All in all, it is clear that...

- To sum up, it can be concluded that...

- From the above analysis, we can see that...

- Therefore, it is highly recommended that...

- In light of the above discussion, we can draw the conclusion that...

- In a word, we should...

- In short, it is imperative that we...

- In a nutshell, we need to...

以上是一些常用的四级作文开头结尾模板万能句型，可以根据自己的实际情况进行灵活运用，提高作文的语言表达能力和文笔水平。同时，需要注意作文的逻辑性和连贯性，保证文章内容的完整和清晰。