标志在哪里缺少PHP？

Question

我在第18行有一些错误-解析错误：语法错误，意外的'。在第18行的********************* \ search \ search_action.php中 错误可能出现在26、29和20行中 search_action.php代码的安全性

$output = '';
$sql = "SELECT * FROM music WHERE name LIKE '%".$_POST["search"]."%'";
$result = mysqli_query($db, $sql);
if(mysqli_num_rows($result) > 0){
    $output .= '<h4 align="center"> Search Result </h4>';
    $output .= '<div class="table-responsive">    

    ';
    while($row = mysqli_fetch_array($result)){
        $output .= '

        <div class="mus_download">
        <div class="main_1_1">
            <div class="name">'.$row["name"];//18
 .' <br> 
            </div>
            <div class="autor">Autor - '.$row["author"];//20 
.'  <br>
            </div>
        </div>
        <div class="main_1_2">
            <div class="song">
                <audio controls loop>
                    <source src="../audio/'.$row["audio"];.' //26 
" type=audio/mp3>
                </audio>
            </div>
            <div class="date">'.$row["date"];//29
.'</div>
        </div>
    </div> <br> <br> 


        ';
    }
    echo $output;
}
else{
    echo 'Data Not Found';
}