【单选题】当调频指数满足( )条件时,称为窄带调频。
【单选题】After completing and signing it, please return the form to us in the envelope ________. [ ]
【单选题】After completing and singing it, please return the form to us in the envelope _________.
【简答题】当调频指数满足( )条件时,称为窄带调频
【简答题】After completing the studies, ______________ (我计划回国在高等学校任教).
【单选题】After completing and signing it, please return the form to us in the envelope _______.
【单选题】当调频指数满足 ____ 时称为窄带调频。