8. Let the set $T=\left\{x_{1}, x_{2}, \cdots, x_{10}\right\}$ have five-element subsets such that any two elements of $T$ appear in at most two subsets. The maximum number of such subsets is $\qquad$ .
8. 8 Detailed Explanation: An element has no more than two opportunities to be in the same subset with other 9 elements, so the number of binary pairs it can form does not exceed 18 times. Since it is a 5-element subset, the number of times this element appears does not exceed 4 times. There are a total of $5 n$ elements appearing in $n$ 5-element sets, thus $5 n \leqslant 4 \times 10, n \leqslant 8$. Furthermore, the sets $\left\{x_{1}, x_{2}, x_{3}, x_{4}, x_{5}\right\},\left\{x_{1}, x_{6}, x_{7}, x_{8}, x_{9}\right\},\left\{x_{1}, x_{3}, x_{5}, x_{6}\right.$, $\left.x_{8}\right\},\left\{x_{1}, x_{2}, x_{4}, x_{7}, x_{9}\right\},\left\{x_{2}, x_{3}, x_{6}, x_{7}, x_{10}\right\},\left\{x_{3}, x_{4}, x_{7}, x_{8}, x_{10}\right\},\left\{x_{4}, x_{5}, x_{8}, x_{9}, x_{10}\right\},\left\{x_{2}, x_{5}, x_{6}\right.$, $\left.x_{9}, x_{10}\right\}$ are 8 subsets that meet the requirements.