Once a blue,Always a blue

Once a blue,Always a blue once in a blue room Once a thife,always a Once a liar,always a Once a red,always reds! “once in a blue 有何出处? Once In A Blue Moon 歌词 once a thief,always a thief?课文 once a gooner always a gooner是什么意思 there is a chance once in a blue moon This is a chance once in a blue moon, Once a red ,always the red . the rule is useful once in a blue Once in a blue moon 这句话话是啥意思啊 I haven't seen her once in a blue moon. once in a blue moon 出处是哪里? once in a blue moon 为什么 解释为 机会难得,绝无仅有? once in a blue moon 意思和once in a while一样嘛?