Answer:
The two basic families of structural systems in architecture are the "shell" and "skeleton-and-skin" systems. The "shell" system relies on a self-supporting, curving surface to bear the load of the building, while the "skeleton-and-skin" system uses a framework of columns, beams, and walls to support the building's weight, with an outer "skin" enclosing the structure.
So, the correct answer to your question would be: the shell and the skeleton-and-skin.