Greatinventionschangethewaywelive,Thefirstgreatinventio...
问题详情：Greatinventionschangethewaywelive,Thefirstgreatinventionwasonethatisstillveryimportanttoday—thewheel.Thismade_ 61 easyformentocarryheavythingsandtotravellongdistances.For _62（century）afterth...