Alone I am 24th. With a friend, I am 20. Another friend, and I am unclean. What am I?
The letter ‘x’. It is the 24th letter of the alphabet, XX in Roman numerals is 20, and XXX is a label for movies that are inappropriate (unclean).
Trên lông dưới lông, tối lồng làm một. Là cái gì?