In Fig.3 we plot the Hubble parameter of the NGCG model in units of $H_{\rm \Lambda
CDM}$ as a function of redshift $z$ range from 0 to 5. The current density parameters used in the plot of Fig.3 are the same as used in Figs.1 and 2. The model parameters are divided into two groups, $\alpha=0$ and $\alpha=0.5$, both including $w_X=-1$, $-0.8$, and $-1.2$. It can be seen from Fig.3 that the NGCG model degenerates to the XCDM when the parameter $\alpha$ takes 0; the cases of $w_X>-1$ and $w_X<-1$ make $H$ larger than and less than $H_{\rm
\Lambda CDM}$, respectively, during the cosmological evolution. The introducing of the interaction parameter $\alpha$ makes $H$ be larger than $H_{\rm \Lambda CDM}$ evidently at early times; while it is interesting to see that the value of $H/H_{\rm \Lambda CDM}$ can cross 1 in the case of $w_X<-1$ in recent period. The acceleration of the Universe is evaluated by the deceleration parameter $q=-\ddot{a}/aH^2$. Omitting the radiation component, the deceleration parameter can be expressed as $$q={1\over 2}+{3\over 2}w_X\Omega_X~,$$ where $\Omega_X$ is given by (\[OmegaX\]). The evolution of the deceleration parameter $q$ is depicted in Fig.3 for selected parameter sets. The current density parameters are 