if p$,$ q and r are propositions, and if only two of them can be TRUE at any given time, which of the following propositional statements are always TRUE? Choose all that apply. $($canvas will deduct points for incorrect selections$)$pv $($q$^$ r$)($p$^$ q$)$ v$($q$^$ r$)$ v$($r$^$p$)$pvqvrp$^($q$^$r$)$