1. The set $A=\left\{x \mid x \in \mathbf{Z}\right.$ and $\left.\frac{600}{5-x} \in \mathbf{Z}\right\}$ has $\qquad$ elements, and the sum of all elements is $\qquad$ .
二、1. 48,240.
Since $600=2^{3} \times 3 \times 5^{2}$, the number of positive divisors of 600 is $(3+1)(1+1)(2+1)=24$.
Therefore, the set $A$ contains $2 \times 24=48$ elements.
Considering that the sum of the elements in $A$ corresponding to two opposite divisors of 600 is 10, the sum of the elements in $A$ is $24 \times 10=240$.