Dear Mr Smith
I am so sorry about that I didn't visit you yesterday. I am expectting you can forgive me . Yesterday, my friend LiHong got a bad cold , and nobody can take care of her .So I have to look after her and not have time to meet you .But i belive you can make sense of me . Because I am losed a important appointment ，I feel very sad. Can we have another meet ? I want to study from you very much.
Looking forward to hearing from you.
Yous,
Li Hua