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【单选题】
一 LTI 系统,输入为 x ( n )时,输出为 y ( n ) ;则输入为 2x ( n )时,输出为 ;输入为 x ( n-3 )时,输出为 。A.
2y （ n ）， y （ n-3 ）
B.
2y （ n ）， y （ n+3 ）
C.
y （ n ）， y （ n-3 ）
D.
y （ n ）， y （ n+3 ）
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