《人类第一个朋友》电影英语完整版高清全集百度云在线观看/迅雷下载,未删减版西瓜影音播放器在线播放。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?