亲爱的张老师，时光匆匆，转眼间三年的时间就过去了。在这三年里，有太多的回忆印在我心头，您的'点点滴滴我永远铭记于心。
Dear Mr. Zhang, time is in a hurry. In an instant, three years have passed. In these three years, there are too many memories printed in my mind, your little bit I will always remember.
亲爱的蔡老师，能成为你的学生我感到万分荣幸，您用您关切的话语激励着我们；您用您的心血哺育了一代又一代的学生。
Dear Mr. Cai, it is a great honor for me to be your student. You inspire us with your words of concern. You have nurtured generations of students with your hard work.
感谢您，亲爱的老师。
Thank you, dear teacher.