Sentence:  Dr. A. V. Astin , NBS Director , <WSD>opened</WSD> the 5 - day session with introductory remarks , following which a total of twenty-six papers were given throughout the week by NBS scientists , from both the Washington and Boulder Laboratories . 
Meaning of the word marked with <WSD> tags:  begin or set in action, of meetings, speeches, recitals, etc.