1. Rov qab sab sealing / 3/4 sab sealing.
2. tuaj yeem ua tiav cov haujlwm ntawm lub hnab ua, ntsuas, pub mis, txhaws, sealing, txiav, suav thiab luam ntawv txiav, tuaj yeem ntxiv cov haujlwm ntawm qhov yooj yim tearing notch.
3.Nrog ua ntej micro computer tswj, kauj ruam lub cev muaj zog tswj lub hnab ntev thiab tus cursor positioning. ruaj khov thiab yooj yim kho.
4.Nrog rau cov kauj ruam-tsawg hloov zaus, kuj tuaj yeem nruab qhov sib txawv pub mis, thiaj li ntim rau particle, kua, muab tshuaj txhuam thiab hmoov khoom.