The teacher told the class the story of a man who swam a river three times before breakfast. Johnny laughed.

老师给同学们讲了一个小故事，说一个人早饭前要在河里游泳，横渡三趟。约翰尼笑了。

"Do you doubt¹ that a good swimmer could do that?"asked the teacher.

老师问道:“你不相信一个游泳很好的人可以做到这个？”

"No，sir，"answered Johnny，"but I wonder why he did not swim it four times and get back to the side where his clothes were."