  We analyze the rest-frame near-UV and optical nebular spectra of three $z >
7$ galaxies from the Early Release Observations taken with the Near-Infrared
Spectrograph (NIRSpec) on the James Webb Space Telescope (JWST). These three
high-z galaxies show the detection of several strong-emission nebular lines,
including the temperature-sensitive [O III] $\lambda$4363 line, allowing us to
directly determine the nebular conditions and abundances for O/H, C/O, and
Ne/O. We derive O/H abundances and ionization parameters that are generally
consistent with other recent analyses. We analyze the mass-metallicity
relationship (i.e., slope) and its redshift evolution by comparing between the
three z > 7 galaxies and local star-forming galaxies. We also detect the C III]
$\lambda\lambda$1907,1909 emission in a z > 8 galaxy from which we determine
the most distant C/O abundance to date. This valuable detection of log(C/O) =
$-0.83\pm0.38$ provides the first test of C/O redshift evolution out to
high-redshift. For neon, we use the high-ionization [Ne III] $\lambda$3869 line
to measure the first Ne/O abundances at z>7, finding no evolution in this
$\alpha$-element ratio. We explore the tentative detection of [Fe II] and [Fe
III] lines in a z>8 galaxy, which would indicate a rapid build up of metals.
Importantly, we demonstrate that properly flux-calibrated and higher S/N
spectra are crucial to robustly determine the abundance pattern in z>7 galaxies
with NIRSpec/JWST.
