Does your girl friend like swimming ?   Yes , she does . She is good at backstroke and free style .   Then you can help her with the breaststroke and sidestroke .   But she wants to learn the butterfly stroke   Really ? Then just ask her to follow me .   I heard you are now practicing underwater swimming , aren't you ?   Yes . But I still have some difficulties it breathing .   Say , kid , keep on practicing , you're sure to be a first-class swimmer . 