2. Which of the following numbers is the largest?
(A) $30^{20}$
(B) $10^{30}$
(C) $30^{10}+20^{20}$
(D) $(30+10)^{20}$
(E) $(30 \times 20)^{10}$
2. Ans: D
$$
\begin{array}{l}
30^{20}=\left(30^{2}\right)^{10}=900^{10} . \\
10^{30}=\left(10^{3}\right)^{10}=1000^{10} . \\
30^{10}+20^{20}=30^{10}+\left(20^{2}\right)^{10}=30^{10}+400^{10}<2.400^{10} . \\
(30+10)^{20}=40^{20}=\left(40^{2}\right)^{10}=1600^{10} . \\
(30 \times 20)^{10}=600^{10} .
\end{array}
$$

Therefore, the largest number is $(30+10)^{20}=1600^{10}$.