BEGIN { n = 3 }

NR == 1 { for (i = 1; i <= NF; i++) { word[$i]++ } }

NR >  1 { counter = 0
          for (i = 1; i <= NF; i++) {
              if (word[$i]-- > 0) counter++ }
          if (counter >= n) print $0
          delete word
          for (i = 1; i <= NF; i++) { word[$i]++ } }