《人类第一个朋友》电影更新至第1集免费在线观看百度云,西瓜影音播放器在播放免费观看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?