Yog lawm, cov khoom siv nce roob kom zoo yog qhov tseem ceeb. Cov neeg nce roob xav tau cov khaub ncaws ntau txheej rau ntau thaj chaw kub sib txawv, cov khaub ncaws sab nraud uas tsis ntub dej, cov tsho tiv thaiv cua sov rau hmo ntuj saum roob, hnab looj tes, kaus mom, thiab khau khiab zoo. Qhov kub ntawm lub roob tuaj yeem poob qis dua qhov khov, yog li kev npaj tseem ceeb heev.