Mr.Black has two cats.One is big and the other is small.He likes them very much.One day,his friend Mr.Green comes to see him.Mr Green is very surprised.He finds there are two holes in the door,a big hole and a small one.He says,"Why are there two holes in your door?"
"To let my cats in and out."Mr.Black answers.
"Why not one?"asks his friend.
"Can the big cat go through the small hole?" Mr.Black says.
布莱克先生有两只猫，一只大的和一只小的。他很喜欢这两只猫。有一天，他的朋友格林先生来看望他，格林先生非常惊讶地发现，门上有两个洞，一个大洞一个小洞。他问道：“为什么你家门上有两个洞？”
“为了让我家猫进出啊”布莱克先生回答道。
“为什么不只弄一个洞呢？”
“大猫能钻得进小洞吗？”布莱克先生说道。

one...the other...：一个是···另一个是···
surprised [sɚ'praɪzd]：吃惊的
go through：通过，经受