since you make delivery before Christmas a firm condition,we deeply regret that we cannot supply you as we have done on so many occasions in the past.特別是最后半句as we have done on so many occasions in the past.該如何翻譯，謝謝．

熱心網友

since you make delivery before Christmas a firm condition,we deeply regret that we cannot supply you as we have done on so many occasions in the past. 既然你使在圣誕節前交貨成為定局，那么我們深感抱歉，我們不能像我們以往很多場合下那樣給你供貨。to have done 表示的是肯定動作,不是 not supply.

熱心網友

因為您堅持要求我們在圣誕節前發貨，很抱歉，以我們的慣例，我們無法給您供貨。最后半句：可以翻譯成，就像過去我們對這種情況的處理一樣。

熱心網友

既然你使在圣誕節前交貨成為定局，那么我們深感抱歉，我們不能給你供貨，正如我們以往在很多這類場合下的做法一樣。