<html> <body> <b>This text is bold</b> <br /> <strong>This text is strong</strong> <br /> <big>This text is big</big> <br /> <em>This text is emphasized</em> <br /> <i>This text is italic</i> <br /> <small>This text is small</small> <br /> This text contains H <sub>2</sub> <br /> This text contains <sup>2</sup> </body> </html>
效果：
参考：http://www.w3school.com.cn/tags/index.asp（包含其它标签，上下节）