Write the equilibrium expression $(K)$ for each of the following reactions.

A$)N_2(g)+O_2(g)2NO(g)$

B$)2$NOCl$(g)2NO(g)+C{l}_2(g)$

C$)()2$

D$)2$CuS$(s)+3O_2(g)2$CuO$(s)+2S{O}_2(g)$