Ava Moffett knew what she was getting into before the girls tennis season ever began back in August. The Burlington High School senior rose to the occasion, both in singles and doubles. With Anna Buxton, the Grayhounds’ No. 1 singles player last spring, graduated, Moffett slid into the top spot after playing No. 2 singles last year. It was a seamless transition. Moffett not only...