$1.06 \pm 0.43$                   $-$                        $-$

   [@BElS]$^{d,\dag}$      $0.64 \pm 0.17$         $0.71 \pm 0.16$        $0.90 \pm 0.31$                   $-$                        $-$

     [@Abada]$^{d}$              $-$              $0.77  \pm  0.29$             $-$                  $-0.57  \pm 0.65$                 $-$

   [@UKQCD]$^{d,\dag}$           $-$                     $-$                    $-$            $(0.22-0.49)^{+13}_{\!\, -8}$           $-$

      [@AmRo]$^{e}$              $-$               $0.48 \pm 0.12$              $-$                         $-$                        $-$

     [@Jaus90]$^{f}$             $-$                     $-$                    $-$                         $-$                       $0.31$

     [@Jaus96]$^{f}$            $0.69$                 $0.78$                  $0.88$                     $0.32$                       $-$

    [@OXT]$^{f,\dag}$            $-$                     $-$                    $-$                       $0.30$                      $0.40$

   This Work$^{\dag}$           $0.66$                 $0.75$                  $0.88$                       $-$                        $-$
  --------------------------------------------------------------------------------------------------------------------------------------------------

  : The form factor $A_{0}(0)$ of $D\rightarrow
  \rho$, $D\rightarrow    K^{*}$, $B\rightarrow   \rho$ and $B\rightarrow K^{*}$ transitions. \[tab1\]

$^{a}$ Quark model\
$^{b}$ QCD sum rules\
$^{c}$ HQET + chiral perturbation theory\
$^{d}$ Lattice calculation\
$^{e}$ Heavy-quark-symmetry\
$^{f}$ Light-front quark model\
$^{\dag}$ $A_{0}(0)$ is directly calculated.

  -------------------------------------------- ---------------------- ----------------------- -------------------------------------------
         $\frac{d\Gamma_{(i)}}{dq^{2}}$         $D\rightarrow \rho $   $D\rightarrow  K^{*}$   $D\rightarrow \rho / D\rightarrow  K^{*}$
    \[0.2cm\] $\frac{d\Gamma_{(0)}}{dq^{2}}$           $4.05$                 $ 4.15$                           $0.97$
   \[0.2cm\] $\frac{d\Gamma_{(+,-)}}{dq^{2}}$          $0.62$                 $ 0.62$                           $1.00$
    \[0.2cm\] $\frac{d\Gamma_{(t)}}{dq^{2}}$           $1.02$                 $1.04 $                           $0.98$
    \[0.2cm\] $\frac{d\Gamma_{(T)}}{dq^{2}}$           $5.69$                 $5.81$                            $0.97$
  -------------------------------------------- ---------------------- ----------------------- -------------------------------------------

  : The first two columns show the partial helicity rates $d\Gamma_{(i)}/dq^{2}$, $i=(0),(+,-),
  (t),(T)$ for longitudinal, transverse, flip and total contributions at $q^{2}=0.087$ GeV$^{2}$ in units of $|V_{CKM}|^{2} 10^{10}$ sec$^{-1}$ GeV$^{-2}$. The last column gives the ratio. \[tab2\]

[99]{} N. Isgur and M. B. Wise, Phys. Lett. 