只此一次，下不为例的英文

once and for all

• 只:    single; lonely
• 此:    this
• 一次:    once
• 下不为例:    not to be taken as ...

例句与用法

1. In compliance with your request , we exceptionally accept delivering against d / p at sight , but this should not be regarded as a precedent
   按你方要求，我方破例接受即期付款交单，但只此一次，下不为例。