The apartment building has wide staircases that make moving furniture easier.

staircases 是名词 staircase 的复数形式，staircase 由 stair（台阶）和 case（框架、结构）组成，指"楼梯"或"楼梯间"，特别强调包括扶手和支撑结构在内的整个楼梯系统。