来自李冠英的问题
ProfessorSmithissaid______anotherimportantdiscoveryinchemistry.a.havingmadeb.havingbProfessorSmithissaid______anotherimportantdiscoveryinchemistry.a.havingmadeb.havingbeenmadec.tohavemaded.tomake
ProfessorSmithissaid______anotherimportantdiscoveryinchemistry.a.havingmadeb.havingb
ProfessorSmithissaid______anotherimportantdiscoveryinchemistry.
a.havingmadeb.havingbeenmadec.tohavemaded.tomake
