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A.2+               B.               C.2+             D.1+

=                                                         (   )

A. 2                 B. 4i               C. 4                D.

=

A.                    B.          C.2             D.

  ＝                                                        

    (A)   0              (B)              (C)2            (D)4 

的值是

A   -2              B                 C  2             D   3