  There are two aspects to the 1995 summer update of the combined preliminary
electroweak data from LEP and SLC. On the one hand, agreement between
experiments and the Standard Model (SM) has improved for the line-shape and the
asymmetry data. The $\tau$ widths and asymmetries are now consistent with
$e$--$\mu$--$\tau$ universality, and all the asymmetry data including the
left-right asymmetry from SLC are consistent with the SM (16\%CL). On the other
hand, a discrepancy between experiments and SM predictions is sharpened for two
observables, $R_b$ and $R_c$, where $R_q$ is the partial $Z$ boson width ratio
$\Gamma_q/\Gamma_h$. $R_b$ is 3\% larger (3.7$\sigma$) and $R_c$ is 11\%
smaller (2.5$\sigma$) than the SM predictions. When combined, the SM is ruled
out at the 99.99\%CL for $m_t>170$GeV. It is difficult to interpret the $11\pm
4$\% deficit of $R_c$, since if we allow only $\Gamma_b$ and $\Gamma_c$ to
deviate from the SM then the precisely measured ratio
$R_h=\Gamma_h/\Gamma_\ell$ forces the QCD coupling to be $\alpha_s\equiv
\alpha_s(m_Z)_{\overline{\rm MS}}=0.185\pm 0.041$, which is uncomfortably
large. The data can be consistent with the prefered $\alpha_s$
($0.10<\alpha_s<0.13$) only if the sum $\Gamma_h=\Sigma_q \Gamma_q$ does not
deviate significantly from the SM prediction. Possible experimental causes for
the under-estimation of $R_c$ are discussed. By assuming the SM value for
$R_c$, the discrepancy in $R_b$ decreases to 2\% (3$\sigma$). The double
tagging technique used for the $R_b$ measurements is critically reviewed. A few
theoretical models that can explain large $R_b$ and small $\alpha_s$ ($=
0.104\pm 0.008$) are discussed. If the QCD coupling $\alpha_s$ is allowed to be
fitted by the data, the standard $S$, $T$, $U$ analysis for a new physics
