描述丰富的课余生活 — 英语填空题

Tom 的课余生活很丰富。On Monday he plays basketball. On Wednesday he paints pictures. On Friday he sings songs. On Saturday he swims in the pool. 请根据上面描述，完成句子：Tom does four activities in his free time. He plays basketball on M___, and he swims on S___. He paints pictures and s___ songs on weekdays.