Sentence:  Young Morris , who , while <WSD>attending</WSD> the University of Pennsylvania , also taught and edited a paper , found time to write Henrietta twenty page letters on everything that engaged his interest , from the acting of Sarah Bernhardt in Philadelphia to his reactions to the comments of `` Sulamith '' on the Jewish reform movement being promulgated by the Hebrew Union College in Cincinnati . 
Meaning of the word marked with <WSD> tags:  be present at (meetings, church services, university), etc.