《探索人类第一个朋友的故事与意义》辽宁传媒学院董雨婷干什么

　　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?