在现代社会中，写一封简短而礼貌的感谢信可以增进人与人之间的良好关系。以下是一个100字左右的英语感谢信范文：
Dear [Recipient’s Name], I would like to express my sincere gratitude for [specific reason]. Your kindness and support have been invaluable to me. I truly appreciate your generosity and thoughtfulness. Thank you once again for everything. Best regards, [Your Name]
这封感谢信不仅表达了对他人的感激之情，还通过具体的理由和真诚的语言加深了对方的印象。