2. Given $\sqrt{24-a}-\sqrt{8-a}=2$. Then $\sqrt{24-a}+\sqrt{8-a}=(\quad)$.
(A) 7
(B) 8
(C) 9
(D) 10
$\begin{array}{l}\text { 2. B. } \\ \sqrt{24-a}+\sqrt{8-a} \\ =\frac{(\sqrt{24-a})^{2}-(\sqrt{8-a})^{2}}{\sqrt{24-a}-\sqrt{8-a}}=8 .\end{array}$

The translation is as follows:

$\begin{array}{l}\text { 2. B. } \\ \sqrt{24-a}+\sqrt{8-a} \\ =\frac{(\sqrt{24-a})^{2}-(\sqrt{8-a})^{2}}{\sqrt{24-a}-\sqrt{8-a}}=8 .\end{array}$