once in a blue moon nghĩa là gì

Ví dụ về once in a blue moon

• It only happens every once in a blue moon.

• I read books once in a blue moon.

• They stand there for weeks and months, and possibly only once in a blue moon does anyone come to remove them.

• Those who do one once in a blue moon inevitably do not produce quite the same results.

• There might be, once in a blue moon, but nine times out of ten a boundary change harms either one party or another.

• But no one plays billiards except for once in a blue moon; it is too eccentric to decide to have a game of billiards.

• This is not something which happens once in a blue moon.

• Soon it will be once every 10 years and then once in a blue moon.