8. (3 points) The last digit of $3^{2003}+4^{2005} \times 5^{2007}$ is
8. (3 points) The last digit of $3^{2003}+4^{2005} \times 5^{2007}$ is $\qquad$ 7.

【Solution】Solution: (1) The cycle of the last digit of the product of several 3s is: 3, 9, 7, 1, with a cycle of four times,

So the last digit of the product of 2003 threes is: $2003 \div 4=500 \cdots 3$, which is the third digit of the 501st cycle, the same as the third digit of the first cycle, which is 7;
(2) The cycle of the last digit of the product of several 4s is: 4, 6, with a cycle of two times, so the last digit of the product of 2005 fours is: $2005 \div 2=1002 \cdots 1$, which is the first digit of the 1003rd cycle, the same as the first digit of the first cycle, which is 4,
(3) The cycle of the last digit of the product of several 5s is: 5, with a cycle of one time, so the last digit of the product of 2007 fives is: 5, $7+4 \times 5=27$,

Answer: The last digit of the expression $3^{2003}+4^{2005} \times 5^{2007}$ is 7.
Therefore, the answer is: 7.