Lub zog qhov kev ua tiav tag nrho muaj plaub yam tseem ceeb:
1. Formulate lub tuam txhab cai cov cai thiab cov txheej txheem
2. Qhov chaw cim qhov muaj zog
3. Qhia neeg ua haujlwm thiab tsim kom muaj kev thaj yeeb nyab xeeb
4. Kho cov neeg ua haujlwm nrog cov cuab yeej thiab cov khoom siv
Hom kev siv hluav taws xob ntau
1. Hluavtaws hloov hluav taws xob
2. Kho txhua yam khoom txhua yam
3. Muab tso tawm thiab tso pa tawm
4. Pneumatic thaiv roj kis kab mob
5. Tshuaj txhuam cov yeeb nkab
6. Thaum tshav kub kub tswj lub ntsuas kub kom sov kub
7. Lwm yam ...
