ring mains

main electrical circuit in a house, etc, off which branch supplies are taken （房子等配电线路的）环形主线.

rightly, rightness, rights issue, rigid, rigidity, rigidly, rigmarole, rigor, rigor mortis, rigorous, rigorously, rigorousness, rigour (US rigor), rile, rim, rime, rimless, rind, ring, ring binder, ring off, ring out, ring road, ring up, ring-finger, ring-pull, ring-shaped, ringer, ringleader, ringlet, ringmaster, ringside, ringworm, rink, rinse, Rio de Janneiro, riot, riot police, riot shield, riotous,