<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> </head> <body> <select> <optgroup label="运动品牌" > <option value ="addidas">addidas</option> <option value ="nick">nick</option> </optgroup> <optgroup label="计算机类"> <option value ="mysql">mysql</option> <option value ="java">java</option> </optgroup> </select> </body> </html>