What levels have 2 skulls?

Games Other Halo
1

…And thats all I wanna know.

2

Library, just done it.
Assault on control room.
Halo, I think thats it.
No skull on Keys
Oh and Silent Cart…2 skulls
So 4 with 2
5 with 1
1 with 0

3

> Library, just done it.
> Assault on control room.
> Halo, I think thats it.
> No skull on Keys
> Oh and Silent Cart…2 skulls
> So 4 with 2
> 5 with 1
> 1 with 0

Thanks