HowtheGrandCanyon(大峽谷)wascreatedremainsoneofthegeology’...
問題詳情：HowtheGrandCanyon(大峽谷)wascreatedremainsoneofthegeology’sgreatestmysteries.SomeevidencesuggeststhattheprocesswasagradualoneinwhichtheColoradoRiver(whichrunsthroughthecanyon)slowlycutdeepera...