1. Delete all perfect squares from the sequence of positive integers $1,2,3, \cdots$, to get a new sequence. The 2003rd term of this new sequence is
A. 2046
B. 2047
C. 2048
D. 2049
Since $44^{2}=1936, 45^{2}=2025$, the 2003rd term of the new sequence is $2003+45=2048$. Therefore, the answer is $C$.