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【多选题】
关于方差的性质，下列说法正确的是
A.
设 C 是常数， X 是随机变量，则D(CX)=C D(X)
B.
设 C 是常数， X 是随机变量,则 D(C+X)=C+D(X)
C.
若 X,Y 为独立随机变量，则 D(X+Y)=D(X)+D(Y)
D.
若 X,Y 为独立随机变量，则 D(X-Y)=D(X)-D(Y)
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