1. If real numbers $a, x$ satisfy $a>x>1$. And
$$
\begin{array}{l}
A=\log _{a}\left(\log _{a} x\right), \\
B=\left(\log _{a} x \right)^{2}, C=\log _{a} x^{2},
\end{array}
$$

then the following correct relationship is ( ).
(A) $A>C>B$
(B) $C>B>A$
(C) $B>C>A$
(D) $C>A>B$
-1 (B).
$$
\begin{array}{l}
\because A=\log _{a}\left(\log _{a} x\right)=\log _{a}\left(\frac{\lg x}{\lg a}\right), 1\left(\log _{a} x\right)^{2}=B>0, \\
\therefore C>B>A .
\end{array}
$$