2. Given $\sqrt{x^{2}+2008}+\sqrt{x^{2}-2006}=$ 2007. Then
$$
3013 \sqrt{x^{2}-2006}-3005 \sqrt{x^{2}+2008}
$$
is ( ).
(A) 2008
(B) 2009
(C) 2010
(D) 2011
2.C.

Let $a=\sqrt{x^{2}+2008}, b=\sqrt{x^{2}-2006}$, then $a^{2}-b^{2}=4014$,
which means $(a+b)(a-b)=4014$.
Given $a+b=2007$. Therefore, $a-b=2$.
Solving, we get $a=1004.5, b=1002.5$.
Thus, the original expression $=3013 b-3005 a=8 b-3005(a-b)$
$$
=8 \times 1002.5-3005 \times 2=2010 \text {. }
$$