Heigh -ho,the dorry -o是什么意思??？急需

一首非常經(jīng)典的英語童謠。
The?farmer in the dell 山谷里有個農(nóng)夫
The farmer in the dell
山谷里有個農(nóng)夫
Hi-ho the derry-o
嗨嗬，唱支歌
The farmer in the dell
山谷里有個農(nóng)夫
The farmer takes a wife
農(nóng)夫娶了個老婆
The farmer takes a wife
農(nóng)夫娶了個老婆
Hi-ho the derry-o
嗨嗬，唱支歌
The farmer takes a wife
農(nóng)夫娶了個老婆
The wife takes the child
老拆敬婆生了個孩子
The wife takes the child
老婆生了個孩子
Hi-ho the derry-o
嗨嗬，唱支歌
The wife takes the child
老婆生了個孩子
The child takes the nurse
給孩子找個了保姆
The child takes the nurse
給孩子找個了保姆
Hi-ho the derry-o
嗨嗬，唱支歌
The child takes the nurse
給孩子找個了保姆
The nurse takes the dog
保姆帶來一信虛條狗
The nurse takes the dog
保姆帶來一條狗
Hi-ho the derry-o
嗨嗬，唱支歌
The nurse takes the dog
保姆帶來一條狗
The dog takes the cat
狗帶來一只貓
The dog takes the cat
狗帶來一只旅坦慎貓
Hi-ho the derry-o
嗨嗬，唱支歌
The dog takes the cat
狗帶來一只貓
The cat takes the rat
貓帶來一只老鼠
The cat takes the rat
貓帶來一只老鼠
Hi-ho the derry-o
嗨嗬，唱支歌
The cat takes the rat
貓帶來一只老鼠
The rat takes the cheese
老鼠帶來一塊奶酪
The rat takes the cheese
老鼠帶來一塊奶酪
Hi-ho the derry-o
嗨嗬，唱支歌
The rat takes the cheese
老鼠帶來一塊奶酪