Dab tsi yog Tsav Cov Ntawv Khob Tshuab Kev Lag Luam? (3)

Tsis tas li ntawd, raws li cov neeg siv kev paub txog kev huv thiab kev tu cev loj hlob tuaj, cov khob ntawv pov tseg tau pom tias muaj kev nyab xeeb dua li cov khob rov qab siv tau, vim lawv raug kub siab thaum lub sijhawm tsim khoom, uas tua cov kab mob thiab ua rau cov khoom yuav luag tsis muaj menyuam. Txawm li cas los xij, qhov muaj cov khoom siv tsis tshua kim xws li yas, Styrofoam, thiab khob khob ua rau muaj kev sib tw tseem ceeb rau cov ntawv khob tshuab ua lag luam.