开首语 meaning in Chinese

opening sentence

In witness whereof , the parties hereto hae executed this agreement in duplicate by their duly authorized representaties as of the date first aboe written
兹证明，双方委派各自代表，在以下开首语中书明的日期签署盖章。本协议一式两份。
In witness whereof , the parties hereto have executed this agreement in duplicate by their duly authorized representatives as of the date first above written
兹证明，双方委派各自代表，在以下开首语中书明的日期签署盖章。本协议一式两份。