root-crop

n crop grown for its edible roots, eg turnips, carrots, etc 根用作物, 块根植物（如萝卜等）.

roof-rack (also `luggage-rack), roof-top, roof-tree, roofing, rook, rookery, rookie, room, room service, room-mate, roomer, roomful, roominess, rooming-house, roomy, roost, rooster, root, root beer, root vegetable, rooted, rootless, rootlessness, rope, rope ladder, rope-ladder, ropiness, ropy (also ropey), Roquefort, roro, rosary, rose, rose-bud, rose-hip, rose-water, rose-window, roseate, rosebay, rosebush, rosemary,