Khoom nta:
1. Cov khoom siv, tus menyuam tseem pub dawb, cov khoom siv Abs, menyuam tsis txhob txhawj txog kev ua ib qho.
2. Cov hniav ntawm cov khej yuav hloov pauv nrog txhua qhov kev ua si.
3. Cov me me thiab zoo dua, yooj yim nqa, nrog txoj hlua khi ntawm tus Tsov tus tw, uas tuaj yeem nqa ib ncig.
4. Cov tsos yog du, puag ncig thiab angular, tiv thaiv tus menyuam mos.