摘要
Welcome to the Changtang National Nature Reserve,a place with annual average temperatures at or below freezing,oxygen about half that of sea level,and a prairie lying at an altitude 5,000 meters high.Found in the northern reaches of the Qinghai-Tibet Plateau,humans can rarely,if ever,be found here,but wildlife abound,many animals among the rarest and most precious in the world.Within such an inferior natural environment,there are groups of special guardians tasked with protecting wildlife from year to year.
