英语作文:假设你叫刘军,你的笔友Jack来信说他的学习成绩不好,并且在最近的考试中数学和历史不及格,回信

Dear Jack,
I am sorry to hear that you have some problem with your study. It doesn't matter. it happens that onw may have his blue days sometimes. I hope you can be confident in yourself and always believe that you can do better. Try to spend more time in maths and history,if you are weak in them. Failure is the mother of success, isn't it? Don't lose heart. Things are going to be OK. i trust you. Anything I can do for you, please tell me.
Love,
Liu Jun