For all three of the cubic lattices (unit cells), all of the ?

and all of the ? are the same size.

A wild guess. edges. radii??
Check it out thoroughly. Perhaps you have a list of words from which to choose.

To determine which parameters are the same size for all three cubic lattices (unit cells), we need to identify the characteristics of cubic lattices.

Cubic lattices have the following features:
1. All edges (sides) of the unit cell are of equal length.
2. All angles between the edges are 90 degrees.
3. All faces of the unit cell are identical and perpendicular to one another.

So, based on these characteristics, we can conclude that for all three cubic lattices, the lengths of the edges are the same size.

Radii, on the other hand, are not consistent across all cubic lattices. Radii are associated with the arrangement of atoms or ions within the lattice, and different cubic lattices may have different arrangements, resulting in different radii.

In summary, the correct answer is that for all three cubic lattices, all of the edges (sides) are the same size.