The correct statement(s) related to oxoacids of phosphorous is(are)

The total number of compounds having at least one bridging oxo group among the molecules given below is
${\mathrm{N}}_2{\mathrm{O}}_5, {\mathrm{P}}_4{\mathrm{O}}_6, {\mathrm{P}}_4{\mathrm{O}}_8, {\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_5, {\mathrm{H}}_5{\mathrm{P}}_3{\mathrm{O}}_{10}, {\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_3, {\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_5$

Under ambient conditions, the total number of gases released as products in the final step of the reaction scheme shown below is