Therevolutionofmachinerycould__________withoutanewsourceofbothmovableandconstantpowerinthenewcentury.
A.be born B.not have been born C.have been born D.have born正确答案B
Therevolutionofmachinerycould__________withoutanewsourceofbothmovableandconstantpowerinthenewcentury.
A.be born B.not have been born C.have been born D.have born正确答案B