Oneday,Mr.Arnoldwasteachingalesson,andthingsweregoin...
問題詳情： Oneday,Mr.Arnoldwasteachingalesson,andthingsweregoingasnormallyasever.Hewasexplainingthestoryofhumanbeingtohispupils.Hetoldthemthat,inthebeginning,menwerenomads(遊牧);theyneverstayedinth...