Classify the following materials into superconductors,conductors,semiconductors,and insulators: $Cu$,$Al$,$Si$,$Ge$,glass,Teflon,$Au$,$Pt$,$CuO$ (at low temperature),graphite,carbon black,and alloys at low temperature.

(N/A) The classification is as follows:
$1$. Conductors: $Cu$,$Al$,$Au$,$Pt$,graphite,carbon black.
$2$. Semiconductors: $Si$,$Ge$.
$3$. Insulators: glass,Teflon.
$4$. Superconductors: $CuO$ (at low temperature),alloys at low temperature.