One possible version：

High school is regarded as the best time in a person’life. As a senior 3 student, it won’t take long before I graduate. Now, I have much to share with my fellow students.

Firstly, I would like to show my appreciation to those standing by me all the way, teachers, parents and friends included. Without their help and advice, my life would be different.

Secondly, I’ve made up my mind to make every effort to study at college,for I believe hard work is the key to success. Meanwhile,physical exercise and recreational activities are also dispensable. Life without sunshine and laughter is bound to be a failure.

Finally I hope that all the younger fellows always keep your dream in mind, by which you will be highly motivated all the time, without doubt or hesitation. Even if sometimes you slack off, tell yourself that tomorrow holds the miracle. Just one more day may be all it will take to realize your dream.

题目分析：本文属于要点作文。1. 写作可以分为四部分。提出写作目的部分，表示感谢部分、对将来的规划部分和个人建议部分。2表示感谢的短语有be thankful to sb for sth; should appreciation to sb for sth ；表述决心计划的短语有make up one’s mind to do sth ; make every effort to do sth ;3在表述三个要点时要用适当的过渡词，使文章衔接紧凑。4尽量使用高级词汇和多种句式，比如定语从句，状语从句等，以提高文章档次。

【亮点说明】作者开门见山提出文章的写作意图，即要和同学们分享高中生活的感想。然后在下文分三个方面分别讲述，中间使用firstly、secondly和finally等表顺序的连接词，使文章层次分明，段落清晰。其中，作者使用了多种句型结构，比如虚拟语气Without their help and advice, my life would be different.；状语从句Even if sometimes you slack off, tell yourself that tomorrow holds the miracle.；定语从句Finally I hope that all the younger fellows always keep your dream in mind, by which you will be highly motivated all the time, without doubt or hesitation.这些句型的使用反应了作者深厚的语言功底。此外，在文中作者还使用了大量的高级词汇，如appreciation，recreational，is bound to，slack off，keep sth in mind 等这也显示了作者丰富的词汇知识，总之这是一篇优秀的范文。