英语六级作文是评估大学生英语写作能力的一个重要环节。要想在六级作文中获得高分，除了语法、拼写、标点等基本要素的正确运用外，更需要掌握一些高级句型，以提升文章的表达力和逻辑性。

下面我们总结了一些常用的英语六级作文高级句型：

1. 表达原因：There are several reasons why... / This can be attributed to... / The main reason is that...

2. 表达影响：This has significant / profound / far-reaching implications for... / This can lead to a variety of problems such as...

3. 表达对比：By contrast / On the contrary, ... / While it is true that..., it is also true that...

4. 表达让步：Although / Despite / In spite of + 名词/动名词/从句, ... / Admittedly, ...

5. 表达强调：It is worth noting that... / What is more / Furthermore / Indeed, ...

6. 表达示范：For instance / For example, ... / As a case in point, ...

7. 表达建议：It is suggested that... / One possible solution is to... / We should take measures to...

8. 表达结论：In conclusion / To sum up / All in all, ...

以上仅是一些常用的高级句型，当然还有更多的表达方式需要我们继续学习和积累。在使用这些高级句型时，需要注意语言的准确性和连贯性，不要过度使用或误用，以免影响文章的质量。同时，也需要注重阅读和写作的练习，才能真正掌握这些句型并将它们运用到实际写作中。