尊敬的李老师，
我非常感谢您在我的论文写作和修改过程中给予的无私帮助。您的指导对我完成这项工作至关重要。
Thank you very much, Ms. Li, for your selfless assistance in the process of my thesis writing and revising. Your guidance was crucial to me completing this task.
再次感谢您的支持与鼓励，期待未来有更多合作机会。
Once again, thank you for your support and encouragement. I look forward to more opportunities to cooperate in the future.
诚挚的，
Sincerely,
张三
Zhang San