1. $[x]$ represents the greatest integer not greater than $x$. In the set $\left\{\left[\frac{1^{2}}{2005}\right],\left[\frac{2^{2}}{2005}\right], \cdots,\left[\frac{2005^{2}}{2005}\right]\right\}$, the number of distinct elements is
A. 1503
B. 1504
C. 1505
D. 2005
1. B If $\frac{(n+1)^{2}}{2005}-\frac{n^{2}}{2005} \geqslant 1$, then $n \geqslant 1002$, at this time $\left[\frac{(n+1)^{2}}{2005}\right]$ and $\left[\frac{n^{2}}{2005}\right]$ are distinct, such elements have $2005-$ $1002+1=1004$; When $\frac{(n+1)^{2}}{2005}-\frac{n^{2}}{2005}<1$, i.e., $n \leqslant 1001$, the difference between two adjacent elements is 1 or 0, such elements have $\left[\frac{1001^{2}}{2005}\right]+1=500$, hence there are $500+1004=1504$ in total.