① I’m sorry I’ve been so slow in answering your letter...
② I have the pleasure (honor) to inform (tell) you that...
③ I must apologize for my delay in answering your letter.
④ I apologize for not writing to you for so long.
⑤ I was really surprised to receive your letter yesterday.
⑥ It was nice to hear from you again.
⑦ I was sorry to hear that...
⑧ Thank you for telling me about...
⑨ I hasten to write you a few lines.
⑩ Please excuse this very short note.
I am glad to hear of your continued success.
As I have not heard from you for long， I feel anxious.
I would have written to you before， but I have had so many things to do that I have not had one moment for myself.
I am very glad to hear that you are all enjoying good health.
Your kind letter afforded me much pleasure.
I am obliged for your prompt and gratifying reply.
We are very happy to say that we are all in the full enjoyment of health.
It was good to hear from you and I shall be very pleased to let you have the information you need.
I’m very pleased to hear that everything is going so well with you and if I can help in any other way， do let me know.
We have enjoyed hearing from you.
发表于 2017-8-6 14:00:15