A method called freeze-fracture can be used to study the structure of cell membranes. The membrane is frozen and then split down the middle, separating the two layers of phospholipids from each other. Any proteins contained within one layer remain in that layer. Proteins which span the membrane can be found in either layer after freeze-fracture, depending on the protein's properties. Which statement(s) about the results of freeze-fracture studies are correct? 1 It provides evidence for the bilayer nature of membranes. 2 It provides evidence for the arrangement of proteins. 3 It shows that the proteins in the membrane do not contribute to its strength.