By the time Michael Phelps retired at 31, he     1     (collect) a total of 23 golds, three silvers and two bronzes at the Olympics, a record that looks unlikely to be broken for many years     2     (come). Phelps suffered hyperactivity disorder as a child and     3     (encourage) to take up swimming at   seven   to   control his   energy.   Over the years   he developed   into a champion swimmer, beating record after record. “I was trying   to see     4     I could really do and where my potential could go” , said Phelps.