英文：Therearemanytheoriesastowhymammothsbecameextinct,suchastherapidwarmingoftheclimate,theoverhuntingofhumans...About20to30thousandyearsago,humansweremakingtoolsthatweremuchmoresophisticatedthanthesimplescrapersofamillionyearsago.Theymadearrowsandspearsoutofrockstoshootmammothsandlearnedtousefiretodrivethemaway.Butthebiggestimpactontheextinctionofthewoollymammothmighthavebeentherapidwarmingoftheclimate.Wecantseemammothswalkinginthesnowanymore.Thencanthey