【正确答案】[范文]
   
Dear senior students,
   Thank you for giving me the opportunity to address you here.
   Time flies without noticing. Now you are about to graduate from our beloved university. On behalf of all the underclass students, I'd like to extend our heartfelt gratitude to you all for taking care of us in life and giving us advice on our study in the past three years. I personally still remember the first day when I came to this university and how warm I felt when you welcomed me and helped me with my luggage all the way to my dormitory.
   On this special occasion, please allow me to congratulate you on your graduation, finding ideal jobs or furthering your study as postgraduates! Whichever way you go, I wish you a bright future. May you more achievement in your future career and more contributions to our society.
   Thank you. Farewell!

【答案解析】 这是一篇发言稿。要求实现三点功能：感谢、祝贺和预祝。根据发言稿的习惯，文章的结构可安排如下：
   第一段：开场白，感谢所有听众给自己发言的机会。
   第二段：代表较低年级的全体学生，感谢毕业生们的帮助，可简要列举实例。
   第三段：祝贺毕业生们顺利毕业、工作或深造，同时预祝所有人前途光明，
   第四段：简要结尾，根据场合需要，道别。