Memory Idioms 2Versión en línea Players will try to match the idiom with it's meaning. por Lunarn Smith Good idea or invention It’s not rocket science Burn the midnight oil Tell a secret Can’t stay calm (relax) because you’re nervous Let sleeping dogs lie Once in a blue moon Let the cat out of the bag Don’t start problems or cause trouble Hold your horses Very expensive Happens very rarely; uncommon Work until late at night Wait and be patient Best thing since sliced bread Cost an arm and a leg Ants in one’s pants It’s not hard.