Hexagonal net qauv tuaj yeem siv rau kev txhawb nqa txoj kab nqes, khawb, pob zeb ntsej muag net mine kev txhawb nqa daim ntawv, kab nqes hav (ntsuab xim), railway kev cais thaiv thaiv, nws tuaj yeem ua rau hauv lub tawb, pad, siv rau dej, dej nyab thiab seawall yaig. tiv thaiv thiab reservoir, dej kaw tawb.Tsav tsheb thiab ...
Nyeem ntxiv