Cov qauv kev ua si sab hauv tsev, tseem hu ua lub tsev fuabtais tsis zoo lossis qhov chaw ua si hauv hav zoov, yog qhov tseem ceeb ntawm txhua qhov chaw lom zem hauv tsev.Lawv muaj thaj chaw me me nrog cov txheej txheem yooj yim xws li swb lossis lub pas dej hiav txwv.Txawm hais tias qee qhov chaw ua si hauv tsev menyuam yaus yog qhov nyuaj, nrog ntau qhov chaw ua si sib txawv thiab ntau pua txoj haujlwm lom zem.Feem ntau, cov chaw ua si zoo li no raug kho thiab muaj lawv tus kheej cov ntsiab lus thiab cov cim tas luav.
Tau txais cov ntsiab lus
Sau koj cov lus ntawm no thiab xa tuaj rau peb
