双层

双层	shuāng céng	double tier / double decker
双	shuāng	variant of 双
双	Shuāng	surname Shuang
双	shuāng	two / double / pair / both / even (number)
层	céng	to pile on top of one another / layer; stratum / floor (of a building); story / (math.) sheaf / classifier for layers