Dear Jim,

I really feel worried about you. You used to do well in your lessons and took an active part in the activities at school. But now you are so crazy about computer games that you have no interest in your schoolwork and don't listen to teachers as carefully as before in class. Also, you can't hand in your homework on time.

Perhaps playing computer games can make you feel relaxed, but if you spend too much time on it, you will have less time to study. And it may do harm to your health. For example, it can hurt your eyes and neck.

I hope you should achieve a balance between your schoolwork and your hobbies. Why not join in some outdoor activities when you feel bored? As your friend, I‘ll be glad to share your happiness and sadness.

Best wishes

这是一篇书信，内容要点已经给出，学生写作的时候切入点容易找。内容贴近学生生活，可以有感而发。要求学生作文涵盖所有要点，并做适当补充或者拓展，使用多种句型和高级词汇，在个人观点方面要紧扣主题，观点明确，做适当发挥。