1. ............ is the central part of a wheel, rotating on or with the axle, and from which the spokes radiate.

Hub

Hup

How

Hubbub

2. ............ is a synonym of hub.

Center

General

Public

Sub

3. ............ isn't a synonym of hub.

Center

Sub

Axis

Capital

4. He has an excellent understanding of route structures and ............ profitability.

hup

hub

hubbub

none

5. ............ isn't a synonym of hub.

Focus

Public

Heart

Core