Lifting saw tsis tuaj yeem hloov pauv ntawm yuav

Kev siv cov saw hlau nqa ntawm cov chaw tsim kho yuav yog feem ntau yog tsis raws cai, ua rau muaj ntau txoj saw ua tsis txaus. Thaum siv txoj saw hlau, tus neeg siv yuav tsum ua "Lifting saw tsis nqa, nqa saw hlau tsis txhob rub tawm", thiaj li ua kom muaj kev nyab xeeb ntawm kev ua haujlwm. Vim li cas thiaj hais li ntawd?
Thaum nqa saw hlau yog siv los nqa cov khoom hnyav, nws tsuas yog xav tau sib tsoo ntawm cov khoom hnyav ntawm cov kev taw qhia hnyav hauv kev sib chwv, thiab yuav tsis hnav; Thaum nqa saw hlau yog siv los nqa cov khoom hnyav, lub ntiajteb txawj nqus cov khoom hnyav yog borne los ntawm cov khoom nqa tawm tsam ib leeg, thiab muaj kev hnav. Yog tias cov saw hlau feem ntau siv rau kev nqa thiab cov saw hlau feem ntau siv rau kev nqa cov khoom lag luam yuav hnav, thiab nws yuav tawg rau thaum nqa khoom hnyav.
Thaum nqa saw hlau siv rau ntawm lub xaib, lub hom phiaj yuav tsum muaj tseeb, txoj saw hluav taws xob tsis tuaj yeem siv rau cov khoom siv hnyav, yog li cov kev pab cuam tsis tuaj yeem siv cov khoom hnyav uas tsis tuaj yeem siv sijhawm ntev dua thiab qhov tshwm sim me me.