Earlyonemorning,morethanahundredyearsago,anAmericaninve...
问题详情:Earlyonemorning,morethanahundredyearsago,anAmericaninventorcalledEliasHowefinallyfellasleep.Hehadbeenworkingallnightonthedesignofasewingmachinebuthehadrunintoaverydifficultproblem:Itseemedimpo...