Languageshavebeencomingandgoingforthousandsofyears,buti...
问题详情：Languageshavebeencomingandgoingforthousandsofyears,butinrecenttimestherehasbeenlesscomingandalotmoregoing.Whentheworldwasstillpopulatedbyhunter-gatherers,small,tightlyknit(联系)groupsdeveloped...