Isosiyete ikora icyuma gishyushya disiki, ...ikigo gikora icyuma gishyushya disiki

Ibicuruzwa byose bikozwe mu cyuma cya boron cyiza cyane, nyuma yo kubitunganya no kubitunganya mu buryo bushyushye, kugira ngo bigire imbaraga zihagije kandi bishobore kwangirika. Ibicuruzwa byoherezwa mu Burusiya, Lituwaniya, Esipanye n'ibindi bihugu, nyuma y'ibizamini byinshi ku isoko byakozwe n'abakiriya, imikorere yabyo ni myiza cyane.