Consider the following matrix: \[ \text { Let } D=\left[\begin{array}{ccc} -1 & -13 & -2 \\ 1 & 3 & -5 \\ 9 & -10 & 7 \end{array}\right] \] Step 2 of 3 : Determine the value of $d_{21}$, if possible. If the element indicated is not in the matrix, state "None".

Step 1 ：Consider the following matrix: \[ D=\left[\begin{array}{ccc} -1 & -13 & -2 \\ 1 & 3 & -5 \\ 9 & -10 & 7 \end{array}\right] \]

Step 2 ：Determine the value of $d_{21}$, if possible. If the element indicated is not in the matrix, state 'None'.

Step 3 ：The element $d_{21}$ refers to the element in the 2nd row and 1st column of the matrix D. We can directly read this value from the matrix.

Step 4 ：The value of $d_{21}$ is \(\boxed{1}\).