2. Kev siv hluav taws xob tuaj yeem tswj tau hauv zos lossis nyob deb
Lub tshuab hluav taws xob lub qhov hluav taws xob tuaj yeem hloov tus nqi hloov pauv lub teeb liab raws li qhov xav tau tiag tiag ntawm qhov chaw. Lub sijhawm no, lub tshuab hluav taws xob valve tuaj yeem ua haujlwm hluav taws xob. Thaum tus xaiv raug kaw hauv qhov chaw lossis thaj chaw deb, nws txoj haujlwm nres tseem ua haujlwm tau zoo; thiab yog tias tus xaiv raug kaw thiab khaws cia hauv lub xeev nres, qhov no pab tiv thaiv qhov chaw lossis hluav taws xob nyob deb.

