英语作文my bastfariend

哦，天啊，是my best friend..您拼错了..
仅供参考哦：
My best friend
I have many friends.But my best friend is Tom.He is 14 years old. He is my best friend because he always helps me a lot.
Yesterday afternoon，we had an exam.The exam was so difficult that I couldn't answer.But I saw Tom was doing it quickly.So，I wanted to write down the answers.But he didn't say anything.After the exam，he asked me that I couldn't answer these questons.I said yes.Then he taught me how to understand the meaning and how to answer these questons.I was very happy because I knew the answers.So，I think Tom is my best friend.