口語課堂第57期:晴天霹靂;破天荒
out of the blue:出乎意料;突然;晴天霹靂
His resignation came right out of the blue. 他的辭職來得很突然.
she had no idea that anything was wrong until he announced out of the blue that he wanted a divorce.
在他突然宣佈要離婚之前,她還不知道出了什麼問題.
once in a blue moon:very rarely 極少;難得;破天荒
Sue's daughter only visits her once in a blue moon.
蘇的女兒很少來看她.