:nth-child(2)
:nth-child(3)
:nth-child(even)
:nth-child(odd)
:nth-child(3n)
:nth-child(3n+1)
:nth-child(3n+2)
:nth-child(3n-1)
:nth-child(3n-2)
1
1
1
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
7
7
7
8
8
8