black box

Другие идиомы:

• as black as a stack of black cats
• as black as pitch
• black eye
• black and white
• in (someone's) black books
• black and blue
• black out
• black market
• as black as the ace of spades
• pitch-black
• as black as night
• as black as coal
• blackout
• as black as a skillet
• put (something) down in black and white