1. Given the equation $|x-20|+|x+20|=2020$ with two solutions $x_{1} 、 x_{2}$. Then $x_{1}+x_{2}=(\quad)$.
(A) 2020
(B) 1010
(C) 0
(D) -2020
-,1. C.
From the symmetry of the function about the $y$-axis, we know that $x_{1}+x_{2}=0$.