1. Cov kev xav tau ntawm cov hlau zoo yog qhov siab. Thaum yuav khoom, xyuam xim rau lub hom thiab zoo kom tsis txhob tawg thiab lwm yam teeb meem.
2. Yog tias siv xaim rau kev kho kom zoo nkauj hauv tsev lossis khoom siv tes ua, xyuas kom lub ntsej muag du thiab burr -dawb kom tsis txhob khawb ntawm daim tawv nqaij.
3. Kev tu cov hlau tseem ceeb heev. Tsis txhob khoov ntau dhau ntawm cov hlau, vim qhov no yuav ua rau nws poob nws qhov kev hloov pauv qub.