18. The characteristic of the positive integer 2013 is that the unit digit is the sum of the other digits, i.e., $2 +$ $0 + 1 = 3$. Among the numbers greater than 1000 and less than 2013, the number of numbers with the above characteristic is ( ) .
(A) 33
(B) 34
(C) 45
(D) 46
(E) 58
18. D.

Consider two cases.
(1) When the thousand's digit is 1, the unit's digit is $a(a=$ $1,2, \cdots, 9)$, so the ten's digit can only be $b=0,1, \cdots, a-1$, giving $a$ choices.

At this point, consider the digit in the hundred's place, which has only $a-1-b$ one choice.
By the multiplication principle and the addition principle, we have
$$
N_{1}=1+2+\cdots+9=45 \text {. }
$$
(2) When the thousand's digit is 2, the unit's digit is $a(a=$ $2,3)$, only 2002.
In summary, there are 46 four-digit numbers that satisfy the condition.