A.質(zhì)量塊 B.導(dǎo)體 C.彈性元件 D.機(jī)器組件
A.2X(f/3) B.2/3X(f/3) C.2/3X(f) D.2X(f)
A.周期偶函數(shù) B.非周期偶函數(shù) C.周期奇函數(shù) D.非周期奇函數(shù)