WGBH's a capella singing competition, "Sing That Thing," will have its fourth season finale on Friday, May 25 at 8:30 pm. The Merrimack Valley Chorus, the first season's adult large group champions, will be joining the show this year for its finale. In honor of the finale, Carol Smolenski, Janet Mulligan, Becky King and Sally Jeffery of the Merrimack Valley Chorus joined us for our news quiz. The chorus serenaded Jim and Margery and answered questions about the week's top headlines.