Chimodzi mwa zinthu zosangalatsa za maswiti ouma mufiriji ndi chizolowezi chake chodzitukumula ndikuwonjezeka kukula kwake panthawi youma mufiriji. Izi si zachilendo chabe; zili ndi tanthauzo la sayansi lomwe limachokera ku kusintha kwa thupi komwe kumachitika nthawi youma mufiriji...