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）