Mawu akuti "stratification" nthawi zina amawopsya phokoso lake lokha, kotero zimamveketsa zasayansi. Komabe, alimi onse odziwa bwino komanso othawa, wokonza minda kapena wamaluwa amatha posachedwa. Tiyeni tiwone chomwe chimapangitsa mbeu kuti ikhale yosakanikirana ndi momwe ingayendetsere bwino. Mukudziwa?