Divisibility Rules for 3, 6 and 9: Complete the missing numbers

Complete the number so that it is divisible by 3 without a remainder:

$?321$

$9$

Complete the number so that it is divisible by 3 without a remainder:

$3_-52$

$2$

Complete the number so that it is divisible by 3 without a remainder:

$632▯$

$7$

Complete the number so that it is divisible by 9 without a remainder:

$427?$

$5$

Complete the number so that it is divisible by 9 without a remainder:

$6?22$

$8$

Complete the number so that it is divisible by 6 without a remainder:

$?51?$

$2,4$

Complete the number so that it is divisible by 6 without a remainder:

$5?3?$

$1,6$

Complete the number so that it is divisible by 6 without a remainder:

$54??$

$4,2$

Complete the number so that it is divisible by 6 without a remainder:

$54??$

None of the above

Complete the number so that it is divisible by 9 without a remainder:

$3?8?$

None of the above