Once i saw a little bird(我曾经见过一只小鸟) Once i saw a bird(我曾经见过一只小鸟) Once i saw a little bird(窗外的小鸟) 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 窗外的小鸟(Once i saw a little bird)