轮毂, 轴心
the central part of a wheel, rotating on or with the axle, and from which the spokes radiate
示例:• The bicycle wheel's hub was greased for smoother rotation.自行车车轮的轮毂被润滑以实现更平稳的旋转。• The spokes connect from the rim to the hub.辐条从轮辋连接到轮毂。同义词:centerpivotaxis