Folding tshuab los yuav ob txhais tes zoo

(1) tus nqi zoo dua
Siv cov twj paj nruag tau sib tw ntau dua li cov twj paj nruag tshiab, thiab cov nqi lag luam kom muaj peev xwm ntau dua, siv cov twj paj nruag zoo dua qub {}}

(2) Cov Khoom Siv Khoom Siv
Cov qib ntawm kev laus ntawm qee cov twj paj nruag muaj tsawg tus qauv thiab tom qab siv tas li yog ruaj khov dua li ntawm cov khoom tshiab .

(3) Cov khoom siv thiab xav tau nyob ruaj khov
Rau cov twj hauv niche thaj chaw, tus lej lossis cov khoom siv tshiab yog qhov ua lag luam me me, ua rau pom kev ua haujlwm ob txhais tes, ua kom yooj yim dua rau kev nrhiav cov khoom nyuaj-rau-tau siv cov khoom nyuaj {}}