關於在國內共同生活的時間,提供的證據可以是親友證明信嗎?
-It may be not enough. You need to provide more evidences such as that school records, medical records, and religious documents, as well as affidavits, insurance, etc., which indicates you are the parent of the child. Anyway, any evidences showing you and the child living together will be helpful, e.g. financial support and day-to-day supervision of the child, and owned or maintained the property where the child resided.
如果可以的話,需要他們寫英文的嗎?
-Translate it into English if written in Chinese.