The duck was very good at swimming, better than the teacher, in fact. He received passing grades in running and flying, but was hopeless in climbing, so they made him drop swimming so that he could practice climbing. After a while he was only average at swimming, but average is still acceptable, at least in school, and nobody worried much about it except the duck.
鸭子非常擅长游泳，实际上，他甚至比老师游的还要好。它通过了跑步和飞翔这两门课，但是就爬树这门课而言，它基本上没有什么希望。所以，他们让鸭子放弃游泳，转而专攻爬树。一段时间之后，鸭子的游泳水平不再出众，仅仅达到了大家的平均水平，而平均水平是可以接受的，至少在学校是这样。除了鸭子自己，没人觉得这有什么不妥。