1. The smallest positive integer $n$ that satisfies $\sqrt{n}-\sqrt{n-1}<0.01$ is
A. 2499
B. 2500
C. 2501
D. There is no such integer
1. C The original inequality is $\sqrt{n}+\sqrt{n-1}>100$. Note that $\sqrt{2500}+\sqrt{2499}>100$ is sufficient.