写一封感谢信给留学高中，可以遵循以下结构和要点：

开头

用正式的称呼，如“Dear [老师/学校领导/招生官]”，并简短地介绍自己。

表达感谢

直接表达感谢之情，提及具体感谢的内容，例如：

感谢学校提供的优质教育资源。

感谢老师们的悉心指导和帮助。

感谢学校提供的住宿和生活条件。

回忆难忘的瞬间

简要描述一些难忘的校园生活或学习经历，展示学校对你的影响。

未来的展望

表达对未来学习和生活的期待，以及对学校的感激之情。

结尾

用正式的结束语，如“Sincerely,”或“Best regards,”并签上自己的名字。

```

Dear [老师/学校领导/招生官],

I am writing to express my deepest gratitude for the support and guidance I have received from [学校名称] during my high school years. Your commitment to our education and personal growth has been truly invaluable.

I particularly want to thank [具体老师姓名] for [具体帮助或指导]，which has played a significant role in my academic and personal development. The opportunities and experiences I have gained at [学校名称] have been instrumental in shaping my future goals and aspirations.

Looking ahead, I am excited to continue my academic journey at [目标大学/机构]，and I am confident that the skills and knowledge I have acquired at [学校名称] will serve me well. I will always cherish the memories of my time at [学校名称] and the support of my teachers and peers.

Once again, thank you for everything you have done for me. I am deeply grateful for your kindness and dedication.

Sincerely,

[你的名字]

```

请根据实际情况调整信件内容，确保表达出你的真实情感和对学校的感激之情。