This book tells the story of: As long as the doorbell rings, Uncle Jian Guai Buguai knows that something magical is going to happen. Uncle Jian Guai Buguai opens the door and sees that there is a post office hippo standing outside the door. The post office hippo opens its mouth as wide as it can and shouts "Hahaha" at Uncle Jian Guai Buguai. Uncle Jian Guai Buguai also imitates the post office hippo, opens his mouth as wide as he can and shouts "Hahaha" at the hippo. Unexpectedly, Uncle Jian Guai Buguai finds that no matter how hard he tries, he can't close his mouth. He walks to the street with his mouth wide open, shouting "Hahaha" at everyone, and as a result, no matter whether it is children or adults, vegetables, fruits or animals, they all can't close their mouths.
本书讲述了：只要门铃叮咚一响，见怪不怪舅舅就知道神奇的事情要发生了。见怪不怪舅舅开门一看，今天门外站着一位邮局河马。邮局河马张开大嘴，能张多大张多大，冲见怪不怪舅舅“哈哈哈”。见怪不怪舅舅也学着邮局河马的样子，张开大嘴，能张多大张多大，冲河马“哈哈哈”。没想到，见怪不怪舅舅发现不管他怎么使劲儿，嘴巴就是闭不上了。他张着大嘴走到大街上，冲着每个人“哈哈哈”，结果无论是小朋友还是大人，无论是蔬菜瓜果还是动物，全都闭不上嘴巴了。
本书讲述了：只要门铃叮咚一响，见怪不怪舅舅就知道神奇的事情要发生了。见怪不怪舅舅开门一看，今天门外站着一位邮局河马。邮局河马张开大嘴，能张多大张多大，冲见怪不怪舅舅“哈哈哈”。见怪不怪舅舅也学着邮局河马的样子，张开大嘴，能张多大张多大，冲河马“哈哈哈”。没想到，见怪不怪舅舅发现不管他怎么使劲儿，嘴巴就是闭不上了。他张着大嘴走到大街上，冲着每个人“哈哈哈”，结果无论是小朋友还是大人，无论是蔬菜瓜果还是动物，全都闭不上嘴巴了。
