Once there was a blind. 
从前有个瞎子。

One day when he was walking, he stepped the head of the dog who was sleeping. 
一天,他正在行路时踩着了一只正在睡觉的狗的脑袋

The dog barked for a while.
狗汪汪汪地叫了一阵。

The blind man went on for miles, this time he stepped the other dog's tail, so this dog barked. 
这人又往前走,这回踩着的是另外一只狗的尾巴,狗又汪汪汪地叫起来。

The blind man had thought that it was the first dog, so he said in surprise, It's a wonder that the dog is so long.
瞎子以为还是那条狗,惊诧地说:奇怪,这只狗可真够长的。