Once i saw a little bird Once i saw a little bird; Once I saw a little bird once I saw A little bird Once I saw a little bird; 31.Once i saw a little bird Once i saw a little bird（窗外的小鸟） 窗外的小鸟（Once i saw a little bird） There was a little bird Once i saw a little bird（我曾经见过一只小鸟）