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The ceiling is the top surface of a building's interior. In interior design, the ceiling can paint, beautify the indoor environment and install chandeliers, light pipes, ceiling fans, open skylights, install air conditioning, change the effectiveness of indoor lighting and air circulation. It is a general term for decorative indoor roof materials. In the past, traditional dwellings mostly used straw mats, reed mats, boards and other main materials. With the progress of science and technology, more and more modern building materials have been applied.