  Let $f_0$ be a polynomial of degree $d_1+d_2$ with a periodic critical point
$0$ of multiplicity $d_1-1$ and a Julia critical point of multiplicity $d_2$.
We show that if $f_0$ is primitive, free of neutral periodic points and
non-renormalizable at the Julia critical point, then the straightening map
$\chi_{f_0}:\mathcal C(\lambda_{f_0}) \to \mathcal C_{d_1}$ is a bijection.
More precisely, $f^{m_0}$ has a polynomial-like restriction which is hybrid
equivalent to some polynomial in $\mathcal C_{d_1}$ for each map $f \in
\mathcal C(\lambda_{f_0})$, where $m_0$ is the period of $0$ under $f_0$. On
the other hand, $f_0$ can be tuned with any polynomial $g\in \mathcal C_{d_1}$.
As a consequence, we conclude that the straightening map $\chi_{f_0}$ is a
homeomorphism from $\mathcal C(\lambda_{f_0})$ onto the Mandelbrot set when
$d_1=2$. This together with the main result in [SW] solve the problem for
primitive tuning for cubic polynomials with connected Julia sets thoroughly.
