第1个回答 2008-01-28
please reply upon your receiving.
第2个回答 2008-01-28
Reply for acknowledgement ASAP.
第3个回答 2008-01-28
Please reply immediately after you receive it
第4个回答 2008-01-28
Please reply as soon as possible.
这是礼貌的说法。
Please reply immediately.
这是直译。