上层

upper layer

used in 上聲|上声[shang3 sheng1]

(bound form) up; upper; above; previous / first (of multiple parts) / to climb; to get onto; to go up / to attend (class or university) / (directional complement) up / (noun suffix) on; above

to pile on top of one another / layer; stratum / floor (of a building); story / (math.) sheaf / classifier for layers

superstructure