What is Aaron Lennox's total crossing score?
Aaron Lennox's refers to T2.player_name = 'Aaron Lennox'; total crossing score refers to SUM(crossing)
SELECT SUM(t2.crossing) FROM Player AS t1 INNER JOIN Player_Attributes AS t2 ON t1.player_api_id = t2.player_api_id WHERE t1.player_name = 'Aaron Lennox'