7. If numbers $a_{1}, a_{2}, a_{3}$ are taken from $1,2, \cdots, 14$ in ascending order, such that $a_{2}-a_{1} \geqslant 3, a_{3}-a_{2} \geqslant 3$. Then the number of all different ways that meet the requirements is $\qquad$ kinds.
Let $a_{1}^{\prime}=a_{1}, a_{2}^{\prime}=a_{2}-2, a_{3}^{\prime}=a_{3}=4$, then $a_{2}^{\prime}-a_{1}^{\prime}=a_{2}-a_{1}-2 \geqslant 1, a_{3}^{\prime}-a_{2}^{\prime}=a_{3}-a_{2}-2 \geqslant 1$, so $a_{1}^{\prime}, a_{2}^{\prime}, a_{3}^{\prime}$ are three numbers taken from $1,2, \cdots, 10$ in ascending order, and vice versa. Therefore, the number of different ways that meet the requirements is $C_{10}^{3}=120$.