Dear Mr/Miss xxx(你老师的姓氏,如Wang,Li等), Time flies!Summer houliday passed soon,and I did a lot of things during it.Let me tell you something interesting. xxx...(介绍一下你的暑假趣事,是在写不出可以去百度一下) It is a little pity that holidays is over, but I'm excited to come back to study with my classmates. Wish you all the best. Yours, (你的名字) xxx