英语竞赛201241.If something happens once in a blue moon.How ofte

It was something that happens once in the blue moon.这是千载难逢的事 Once In A Blue Moon 歌词 请问 once in blue moon This is a chance once in a blue moon, Once in a blue moon 这句话话是啥意思啊 once in a blue moon 为什么 解释为 机会难得,绝无仅有? "I haven't seen her once in a blue moon. once in a blue moon 出处是哪里? 求魂音泉的once in a blue moon的罗马音 once in a blue moon 意思和once in a while一样嘛? it happend once in the blue moon there is once in blue moon i havetogotowork,it's a blue Mond