(1) Ua raws li cov txheej txheem kev khiav hauj lwm nruj me ntsis thiab kev tsav tsheb tseem ceeb kom tsis txhob hloov cov iav thiab txo cov iav hnav.
(2) nruj me ntsis siv cov txheej txheem tu thiab ntxiv dag zog rau kev tu lub iav hloov khoom siv. Thaum lub iav hloov cov cuab yeej txuas txuas tsis zoo, nws yuav tsum tau hloov kho raws sij hawm kom ntseeg tau tias kev ua haujlwm zoo ntawm cov iav hloov khoom siv.
(3) Ua tib zoo saib xyuas thiab saib xyuas ntawm tus kheej-locking mechanism. Rau kev tso cov pob hlau, cov pob zeb, thiab hloov cov diav rawg uas tau txo lossis poob qhov kev ua tau zoo, lawv yuav tsum tau kho lossis hloov raws sijhawm kom ntseeg tau tias qhov kev ua haujlwm ntawm tus kheej ntawm tus kheej lub ntsuas phoo yog qhov zoo.
(4) Thaum sib sau ua ke cov kis tau tus mob, nws yog ib qho tsim nyog yuav tsum ua raws li cov txheej txheem kev khiav hauj lwm kom ntseeg tau tias tag nrho cov khoom ntawm kev sib kis tau raug kho kom raug thiab nruj kom tsim nyog. Thaum tsav tsheb ntawm txoj kev nce toj siab, cov neeg tsav tsheb yuav tsum nruj me ntsis ua raws li cov lus qhia rau kev nqis qis qis thiab yuav tsum tsis txhob ua txhaum cai.
