<https://jackteacher.cc/tag/%e7%b6%b2%e8%b7%af%e8%a1%8c%e9%8a%b7%e6%8a%80%e5%b7%a7/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://jackteacher.cc/tag/%E7%B6%B2%E8%B7%AF%E8%A1%8C%E9%8A%B7%E6%8A%80%E5%B7%A7/>