英语书信开头问候语英文写信开头问候语英文电邮邮件开头礼貌问候语

6、I was very happy to receive your letter of October 10th.我很高兴收到你10月10日的来信。

7、I’m so sorry for not having written to you for such a long time.十分报歉，很久没有给你写信了。

8、I’m sorry I took so long to reply.很报歉给你回信晚了。