$1 \cdot 11$ If $a b c>0$, then $\frac{|a|}{a}+\frac{|b|}{b}+\frac{|c|}{c}-\frac{a b c}{|a b c|}$ is
(A) 2.
(B) -2.
(C) 2 or -2.
(D) None of the above.
(China Hubei Province Huanggang Junior High School Mathematics Competition, 1993)
[Solution] Suppose $a, b, c$ are all greater than 0, or two of them are less than 0 and the other is greater than 0.
(1) $a, b, c$ are all greater than 0;

Original expression $=1+1+1-1=2$.
(2) Two of $a, b, c$ are less than 0, and the other is greater than 0.

By symmetry, assume $a>0, b<0, c<0$.
Original expression $=1-1-1-1=-2$.
Therefore, the answer is $(C)$.