It seems like you're looking for a term to complete the statement about how a solid is held in shape. The correct choice here would be "intermolecular forces."
So the complete statement would read: "A solid is held in shape by strong intermolecular forces."
These forces include ionic bonds, covalent bonds, hydrogen bonds, and van der Waals forces, which help maintain the structure and stability of solid materials. If you have any further questions or need clarification, feel free to ask!