hub
/hʌb; hʌb/ n
1 central part of a wheel from which the spokes radiate 轮毂. =>illus at App 1 见附录1插图, page xiii.
2 (fig 比喻) central point of activity, interest or importance （活动、 兴趣或要务的）中心
a hub of industry, commerce, etc 工业、 商业等中心
He thinks that Boston is the hub of the universe. 他认为波士顿是世界的中心.