问如何将HTML标记自动添加到.txt文件中的不同行中？

EN

for i in `seq 1 6 30`; do sed -n "${i}p" sample.txt; done

1 Question
7 Question

for i in `seq 1 6 30`; do sed -i -E  "${i}s/(^.*)/<questiontag>\1<\/questiontag>/g" sample.txt; done

for i in `seq 1 6 30`; do qs=$(($i+1)); qe=$(($i+5)) ; sed -i -E  "${qs},${qe}s/(^.*)/<answertag>\1<\/answertag>/g" sample.txt; done

<questiontag>1 Question</questiontag>
<answertag>2 Answer 1</answertag>
<answertag>3 Answer 2</answertag>
<answertag>4 Answer 3</answertag>
<answertag>5 Answer 4</answertag>
<answertag>6 Answer 5</answertag>
<questiontag>7 Question</questiontag>
<answertag>8 Answer 1</answertag>
<answertag>9 Answer 2</answertag>
<answertag>10 Answer 3</answertag>
<answertag>11 Answer 4</answertag>
<answertag>12 Answer 5</answertag>

for i in `seq 1 6 $(wc -l < sample.txt)`; do sed -n "${i}p" sample.txt; done

\d+\sQuestion(.*$)\s\d+\sAnswer(.*)\s\d+\sAnswer(.*)\s\d+\sAnswer(.*)\s\d+\sAnswer(.*)\s\d+\sAnswer(.*)

<h1>$1</h1>\n<ol>\n<li>$2</li>\n<li>$3</li>\n<li>$4</li>\n<li>$5</li>\n<li>$6</li>\n</ol>

if((n-1)%6 === 0) // Question
else // Answer

$file = 'my/file.txt'
$contents = file($file);
$result = [];

$regexes = [
    'question' => [
        'regex' => '/^(\d+\s.+?\s?(?<!\d))$/gm',
        'replace' => '<div>$2</div>'
    ],
    'answer' => [
        'regex' => '/^(\d+\s)(.+)(\s\d+)$/gm',
        'replace' => '<div>$2</div>'
    ]
];
foreach($contents as $line) {
    foreach($regexes as $regex) {
        if(preg_match($regex['regex'], $line)) {
            $result[] = preg_replace($regex['regex'], $regex['replace'], $line);
        }
    }
}