1. Lub tshuab nqa yuav tsum pib rau sab caj npab, tom qab ntawd lub caj npab, thiab thaum kawg sab caj npab. Thaum lub sijhawm ua haujlwm ntawm qhov chaw nce lifting, nws yuav tsum tau hloov tom qab nqa thiab tshem ntawm qhov siab. Cov kev sib hloov yuav tsum qeeb, thiab xyuam xim rau qhov kev sib tsoo caj npab thiab lub khawm nruab ntug. Seb tus nrug ntawm txhua yam khoom siv raws li kev ruaj ntseg xav tau.

2. Lub chaw ua haujlwm ntawm kev tsav tsheb yuav tsum pib lub tshuab tshem tawm tom qab ua ntau yam kev kuaj xyuas thiab kev txij nkawm raws li kev tswj cov kev cai ntawm cov khoom siv kho tshuab. Ua ntej ua haujlwm, xyuas cov haujlwm ua haujlwm ntawm qhov chaw nce kom tshem tau obstacles uas tabkaum cov kev sib hloov thiab kev taug kev ntawm kev nqa cov tshuab.

3. Kev txhawb nqa yog ib txoj hauj lwm tseem ceeb tshaj plaws rau kev khiav lag luam ntawm qhov chaw nce. Hauv av yuav tsum tau xaiv. Yog hais tias lub hauv paus yog muag muag los yog tsis muaj zog, nws yuav tsum tau matted nrog tus neeg pw tsaug zog ua ntej nws tuaj yeem ua haujlwm.