2. Tag nrho cov txheej txheem yog "floating", uas zoo heev txo lub zog noj ntawm cov neeg ua haujlwm tuav cov khoom ua haujlwm.
3. Nruab nrog lub tshuab nres kom zoo xauv qhov sib koom ua ke kom tsis txhob ya raws.
4. Gas tawg tiv thaiv thiab tswb, nws tus kheej-xauv kom tsis txhob ntog thaum huab cua siab poob.
5. Qhov chaw tiv thaiv thiab tswj cov cuab yeej kom tsis txhob muaj kev sib tsoo thiab cov plua plav, thiab xyuas kom muaj kev ruaj ntseg ntawm cov khoom precision.