$\underset{\text{fsdfdsf}}{\stackrel{VI}{S}{O}_4^{2-}}+\stackrel{-}{e}\underset{-H_{2}O}{\stackrel{T,p}{\rightleftarrows }}{\left[Cu{\left(OH\right)}_4\right]}^{2-}$  

 

${}_{54}^{43}P$  

 

$O_2\uparrow +Zn\to CaO\downarrow$     

 

$\sout{\text{[}}C{H}_2-CH=CH-\stackrel{\underset{\mid \mid }{O}}{C}\sout{\text{]}}$