As school districts prepare for the start of the session, Education Commissioner Mark McQuillan says there is plenty to celebrate, but low test scores continue to be of concern for officials. He says, last year, 20.4 percent of Connecticut public school students scored below basic in 3rd grade reading on the CMTs  and  20.6 percent in the class of 2007 SAT-takers scored over 600 on reading. Over half a million students are expected to begin school in the coming weeks. McQuillan says although that number is down by a percent, the decline was anticipated, and opened up space for some schools to offer preschool programs.