2. The solution to the equation $10^{x} \times 100^{2 x}=1000^{5}$ is ( ).
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
2. C.

Taking the common logarithm on both sides, we get
$$
\begin{array}{l}
x \lg 10+2 x \lg 100=5 \lg 1000 \\
\Rightarrow x+4 x=5 \times 3 \Rightarrow x=3 .
\end{array}
$$