1. Given real numbers $a$, $b$, $c$ satisfy $a^{2}+2 b=7$, $b^{2}-2 c=-1$, $c^{2}-6 a=-17$. Then the value of $a+b+c$ is ( ).
(A) 2
(B) 3
(C) 4
(D) 5
-、1.B.
Adding the three equations and completing the square yields
$$
(a-3)^{2}+(b+1)^{2}+(c-1)^{2}=0 .
$$