@font-face导入字体无效

代码:

html>
<html>
    <head>
        <meta charset="gb18030">
        <style>
            @font-face{
                font-family:th;
                src:url(https://mdl-fs.mail.163.com/mdriver-serv-download/file/download?key=djAyczJ4VzM5Rzd5VXRlMGhuUlRmdnU0dzRqL2dJZVZaNW1VMVVteGFlbHFKbz0&token=048b215af23445fda4f090971b52df11&proof=N21pbG4vcWpHNHl2RkllaitZekVMazA1cU5rbG14Z0NsOXRkczZZank5TkJLUU9lQWFvZjFIZGZ1SDlEOVRCYUhOQWlwZGVScWhXTkZuaWgvRkNiSjJ5TjZBeE5xT2sxY2FrcUF1aTd5Z0RQUzJ6cEphcWEya1EvSDlHNGN4MmZvM1JRZW1wdTVWNnF4dVNMTmJzWXgwT0Y4NUJTTnh2STdyRDNNMDhLdFRLVXUwQmVVdWRlaFM2ZlNiRysyMDFTTE9peUVDZUE5MkZBQlVVQzAwQ1Z3NjdwZkFFVGZKaTZZNS85bEd1bytUYz0=&dlKey=0acb3eb5330f45fc8891da3b34f772e5) format("ttf");
            }
        style>
    head>
    <body>
        <p style="font-family:th;font-size:16em;">p>
        <p style="font-size:16em;">p>
    body>
html>

第一与第二行显示完全一样,导入字体库不起作用,为何?

1.检查一下字体文件路径是否正确
2.引入的后缀名为.ttf的字体的format()不是ttf,而是 truetype ,format('truetype')

引入字体不是ttf文件