The ancient kind of closet how to open ah?

Ancient woodwork used mortise and tenon structure, which is a combination of concave and convex connection on the two wooden members. Convex ancient wood using mortise and tenon structure, is used in two wooden members of a concave-convex combination of the connection. The convex part is called tenon (or mortise and tenon); the concave part is called mortise (or mortise and tenon, mortise and tenon groove), which is the main structure of ancient architecture, furniture and other wooden instruments. If the mortise and tenon is used properly, the two pieces of wood structure can be tightly fastened between.