8. Arrange all three-digit numbers formed by the four digit cards $0$, $1$, $2$, $2$ in descending order, the 2nd number is
$\qquad$, the difference between the 4th number and the 8th number is $\qquad$ -
Answer: $220$; $90$
Explanation: The three-digit numbers formed, from largest to smallest, are: $221$, $220$, $212$, $210$, $202$, $201$, $122$, $120$, $102$. The 2nd is $220$; the 4th is $210$; the 8th is $120$; the difference between the 4th and the 8th number is: $210-120=90$