编辑下面的代码:
【加编码】
查看效果 »
<html> <head> <style> p:only-of-type { background:#ff0000; } </style> </head> <body> <div><p>This is a paragraph.</p></div> <div><p>This is a paragraph.</p><p>This is a paragraph.</p></div> </body> </html>
结果:
【此窗口】
帮助？