Flagsarenowseeneveryday,buttheywereonceonlyusedinbattle...
问题详情：Flagsarenowseeneveryday,buttheywereonceonlyusedinbattles.Nooneknowsforsure___61___flagscamefrom.However,itseemsthatChinaandtheRomanEmpirewerethefirstonestousethemtoidentifytheirarmies.The___62...