The Celtics had a busy, do-gooding Thursday. In the afternoon, players Jason Terry and Terrence Williams read to students at the Perkins School for the Blind, and were interviewed on the school’s student-run radio station. They were joined by team co-owner Wyc Grousbeck and his wife, Corinne, who’s a Perkins trustee, as well as the team’s in-arena host, Molly McGrath. A few hours later, Paul Pierce hosted his Truth Strikes Again celebrity bowling tournament to benefit his campaign to fight child obesity. The guest list for the night, held at Kings Dedham, included Pierce’s friends Kevin Garnett, Avery Bradley, Chris Wilcox, Jeff Green, Courtney Lee, Doc Rivers, and JAM’N 94.5’s Ramiro Torres.