L3 : CFL , L4 : CFL , L5 : Regular
L1=( CFL ∪ CFL )c = (CFL)c // CFL , closed under union , but not closed under complement
L1=(CFL)c // as CFL is not closed under complement then go to next upper class , like every CFL is CSL , so in that way L1 = (CSL)c // CSL closed under complement so , in that way L1 is atleast CSL , it may or may not CFL
L2 : ( (CFL)R ∪ CFL ) ∩ Regular // CFL closed under R and union so
L2 = (CFL ∪ CFL) ∩ Regular = CFL ∩ Regular = CFL // Closure property :: ( L∩Regular=L )