假如你是John，你的好友Julia最近心情不好，请你更具她的来信给她些一份回信，提出具体的建议，帮助他解决问题。注意书信格式，80词左右。
Dear John,
I really can't stand my cousin. Sheoften borrows my school things, but she never returns them in time. Last weekend, she took away my math book without my permission, I couldn't finish my homework. I don't want to argue with her because shi is my aunt's daugher and my aunt loves me very much. I don't know what to du . Can you help me ?
yours,
Julia