2. The remainder when the number $104^{2006}$ is divided by 29 is ( )
A. 5
B. 27
C. 28
D. 13
2. C Hint: $104=4 \times 29-12$,
$$
\text { so } \begin{aligned}
104^{2006} & \equiv 12^{2006}(\bmod 29) \\
& \equiv 144^{1003}(\bmod 29) \\
& \equiv(29 \times 5-1)^{1003}(\bmod 29) \\
& \equiv(-1)^{1003}(\bmod 29) \\
& \equiv 28(\bmod 29) .
\end{aligned}
$$