在专四英语作文结尾段，使用合适的开头连词可以使文章结构更加清晰，逻辑更加严密。以下是一些常用的开头连词：

1. Therefore: 表示因此、所以，用于引出结论。
e.g. Therefore, it is crucial to take immediate action to protect the environment.

2. Consequently: 表示结果、因此，用于引出结果或推论。
e.g. Consequently, we can conclude that hard work is the key to success.

3. In conclusion: 表示总结，用于引出文章或段落的总结性观点。
e.g. In conclusion, education plays a vital role in personal and social development.

4. In summary: 表示概括、总结，与"In conclusion"类似。
e.g. In summary, effective communication is essential in both personal and professional relationships.

5. Finally: 表示最后，用于引出最后一个观点或建议。
e.g. Finally, I suggest that we should cherish every opportunity to learn and improve ourselves.

6. Moreover: 表示此外、而且，用于添加额外的观点或支持性信息。
e.g. Moreover, exercise is not only beneficial for physical health but also for mental well-being.

7. Furthermore: 表示进一步地、此外，与"Moreover"类似。
e.g. Furthermore, technological advancements have revolutionized the way we live and work.

8. Hence: 表示因此、所以，与"Therefore"和"Consequently"类似。
e.g. Hence, we should attach importance to the development of renewable energy sources.

9. Thus: 表示因此、所以，用于引出结论或结果。
e.g. Thus, it is evident that perseverance is essential for achieving success.

10. As a result: 表示结果，用于引出结果或影响。
e.g. As a result, the government has implemented strict regulations to protect endangered species.

以上这些开头连词可以帮助你在专四英语作文结尾段中更好地表达观点，使文章更具连贯性和多样性。希望这些连词能对你的写作有所帮助！如有其他问题，请随时提问。祝您写作顺利！