console 命令行工具 X clear
console
<!DOCTYPE html>
<html>
         <head>
         </head>
         <body>
             <svg width="100%" height="100%" version="1.1"
xmlns="http://www.w3.org/2000/svg">

             <rect width="300" height="100"
style="fill:rgb(0,255,0);stroke-width:1;
stroke:rgb(0,0,0)"/>
<circle cx="100" cy="50" r="40" stroke="black"
stroke-width="2" fill="red"/>

</svg>
         </body>

</html>