4、ningwhentheenemycame. Itwasverydifficulttobuildsuchawallintheancientdayswithoutanymodernmachines.Alltheworkwasdonebyhand.Thousandsofmendiedandwereburiedunderthewalltheybuilt.TheGreatWallwasmadenotonlyofstoneandearth,butofthefleshandbloodofmillionsofmen. Toda