Side Kangakanani Iwaranti Yezibani Zobufakazi Bokuqhuma

Amanye amalambu angaqhumi afika newaranti yeminyaka emi-5. Nokho, isikhathi esijwayelekile sewaranti yezibani ezingaqhumi ngu 3 iminyaka.

Njengoba izibani ezingaqhumi ziguga, imithombo yabo yokukhanya ivame ukuncipha ngamandla. Ngenkathi amanye ama-bulb angahlala iminyaka emihlanu, inkinga eyinhloko ivamise ukuba nomthombo wokukhanya ngokwawo. Ngemva kweminyaka emihlanu, amanye ama-bulb angase ayeke ukusebenza.