单词blue moon
n.: 极长的一个时期；一个月中的第二个满月
网络: 蓝月亮；蓝色月亮；月满抱西环
一个月中的第二个满月,由于每29.5天才会出现一次满月, 所以一个月内出现第二个满月的几率很小
极长的一个时期
复数：blue moons
How can you let such a golden opportunity to make big money slip through your fingers? It was an opportunity that comes once in a blue moon.
这样一个发大财的机会千载难逢，你怎么能眼睁睁地让它溜掉呢。
In recent years, we don"t often get a chance to visit our grandparents. They live so far away. We get to see them once in a blue moon.
最近几年，我们很少有机会去看望祖父母。他们住的太远了，见一面真有千载难逢之感。
His parents are very strict with him and allow him to go out with his pals in the evening only once in a blue moon.
他的父母亲对他很严格，难得准许他和朋友们在晚上一起出去。
Sally: Wow, this is really a chance once in a blue moon. Please invite me to go with you!
哇，这真是千载难逢的好机会。求求你邀请我跟你一起去嘛！
But I tell you I talked to no one this morning. And I was alone with you at the Blue Moon.
但我告诉你，今天早上我除了跟你在蓝月没有和别人说过话。
Did you meet anyone while you were waiting on the sidewalk for me to come out of the Blue Moon?
你在路边等我出来的时候没有遇见任何人么？
It"s a blue moon that she is not in the moon to look into the matter.
她没有情绪调查此事真是一件罕见的事儿。
He is not very keen on swimming. Only once in a blue moon do we meet him in the swimming pool.
他不喜欢游泳，我们很难得在游泳池遇到他。
Since our parents live so far away, in recent year we get to see them once in a blue moon.
因为父母住在远处，所以我们近来很少和他们见面。
Since our parents live so far away, recently we get to see them once in a blue moon.
因为父母住得比较远，所以我们近来很少和他们见面。