4.设A,B是任意两个概率不为零-|||-的相互独立事件,则必有 () .-|||-A (Acup B)=P(A)+P(B)-|||-B (Aoverline (B))=P(A)P(overline (B))-|||-(overline (A)B)neq P(overline (A))P(overline (B))-|||-D P(A-B)=P(A)