Artificial Nyom: Recycling
Muaj qhov kev pabcuam rov ua dua tshiab zoo siab ntawm Yellowstone National Park, hu ua Project Yellowstone. Cov neeg tuaj xyuas Yellowstone Park tso cov fwj yas rau hauv cov khoom siv thoob plaws hauv lub tiaj ua si, thiab cov yas rov qab siv dua los tsim cov nyom nyom. Cov khoom siv rov qab siv dua yog siv rau cov khoom siv hluavtaws zoo tshaj plaws, pab khaws cov khib nyiab tsis tsim nyog tawm ntawm qhov chaw pov tseg. Cov nyom dag kuj suav nrog cov nroj tsuag taum pauv, uas yog 100% cov peev txheej txuas ntxiv mus, rau hauv cov nyom nyom.
