Txhawm rau txhim kho lub elevator hauv ib lub tsev, peb siv cov ntaub ntawv txhuas rau ob qho tib si ncej thiab elevator cabin.Qhov chaw yog tag nrho siv rau kev tsim kom zoo dua qub, tshwj xeeb tshaj yog lub tsev loj loj.Nyob rau tib lub sijhawm, cov ntaub ntawv aluminium tuaj yeem nthuav tawm sab nrauv zoo dua.Qhia qhov noblity ntawm the tus tswv.