Look ! Mom , that's amazing ! I can't believe the girls have so neat movements .   Yeah , they all received very strict training . A minute on the stage takes ten-year practice .   And all their movements are so elegant . It seems like dancing in the water .   Exactly , you know , water ballet puts dancing , music and swimming together .   There you go ! Daddy has told me that water ballet is also called Synchronized Swimming .   That's my boy ! Katherine Curtis created this activity in 1920 . And in 1984 , it was authorized as one activity in Olympic Games .   Wow , Mom is more knowledgeable than Dad . I must learn from you .   My little boy , you should learn more from me . I'm almost thirty years older than you .   OK , you're the boss . Look , Mom , one guy has just jumped into the swimming pool .   Oh , my God . It's so dangerous . And he might break his leg . You mustn't do anything like that . 