Mabhegi anotenderera akagadzirwa rini?
Chikwama chinotenderera chakagadzirwa naBernard D. Sadow muna 1970. Kugadzira kwake kwakatsanangurwa mupatent, yakaverengwa 3.653.474, iyo yakasimbisa kukura kwokufamba nendege somugariro wokushandisa unokurudzira. Kufuridzirwa kunonzi kwekubatanidza mavhiri zvakananga kumikwende kwaive kucherechedzwa naSadow kweanotakura zvinhu achirongedza mukwende pane ngoro inotenderera.