134 Choose six different numbers from $1,2, \cdots, 49$, where at least two are adjacent, the number of different ways to choose is
A. $C_{49}^{6}$
B. $C_{44}^{6}$
C. $C_{49}^{6}-C_{44}^{5}$
D. $C_{49}^{6}-C_{44}^{6}$
134 D. Let $a_{1}<a_{2}<\cdots<a_{6}$ be chosen from $1,2, \cdots, 49$. $a_{1}, a_{2}, \cdots, a_{6}$ are not adjacent, i.e., $a_{1}<a_{2}-1<a_{3}-2<a_{4}-3<a_{5}-4<a_{6}-5$ are six different numbers chosen from 1 to 44, with $C_{44}^{6}$ ways.