a letter in reply; write back

1. 回信免費郵寄至牛津牛津大學出版社宣傳部。
   Reply to Publicity Department, FREEPOST, Oxford University Press, Oxford.
2. 她盡管很想再見到他，但卻不愿給他回信。
   Despite wanting to see him again, she refused to reply to his letters.
3. 我正寫一封鄭重其事的回信。
   I'm composing a formal reply to the letter.
4. 簡給他寫了封長信，然而他一直沒有回信。
   Jane wrote him a long letter, but he never wrote back.
5. 任他沒完沒了地給我寫信，我就是不回信。
   He can write me letters till he's blue in the face, I'm not going to reply.
6. 我沒收到回信。
   I had no reply to my letter.
7. 他不給我回信使我百思不解。
   I am puzzled by his failure to reply/that he hasn't replied to my letter.
8. 回信時請注明我方函件編號。
   Please quote our reference when replying.

信的英語翻譯：