下面这些单词添加一个字母、去掉一个字母或改变一个字母都能变成另外一个单词,看谁变得多.

问题描述:

下面这些单词添加一个字母、去掉一个字母或改变一个字母都能变成另外一个单词,看谁变得多.
hour
past
than
red
buy

hour  our  four  tour  sour  pour
past   part  last  fast cast pass pant  pase
than   then  that hand thank 
red   read  led  rid bed
buy    by  bay bus  guy  busy