 class="op">(</span><span class="va">cntl</span>,<span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"schoolid"</span>,<span class="st">"pv1math"</span>,<span class="st">"st29q03"</span>,<span class="st">"sc14q02"</span>,<span class="st">"st04q01"</span>,</span></span>
<span class="r-in"><span>                       <span class="st">"escs"</span>,<span class="st">"w_fschwt"</span>,<span class="st">"w_fstuwt"</span><span class="