写作。

Dear Prof. Wang,
First of all, please allow me to express my deep sorry for not being able to keep our appointment. I do know that this is very impolite and must have caused you much trouble.
I do reckon that at present any explanation is pale and futile. However I do not want you to misunderstand me. of a my way to your office, an old lady suddenly fainted due to heart attack on the bus. I stopped a taxi and sent her into a nearby hospital. I stayed there until her son came, which spoiled our appointment.
I am aware that our appointment is of importance. I do hope that you would be kind enough to spare your valuable time to meet me. I am looking forward to hearing from you.
Sincerely yours, Li Ming