人类的第一个朋友

He has shared our lives for 20,000 years. Along the way, he has helped us find food, kept our livestock, protected us from our enemies, guided us in extreme conditions, and saved us from peril. Now, he comforts us, relieving loneliness and helping us cope with old age. How did dogs come about?人类的第一个朋友无弹窗在线观看地址来源于互联网，西钰影院免费提供纪录片《人类的第一个朋友》全集高清完整版在线观看服务。