Question

进入页面后，会在网站头部出现一幅图片广告，30秒钟后自动消失，这个效果怎样实现的

进入页面后，会在网站头部出现一幅图片广告，30秒钟后自动消失，这个效果怎样实现的
如sina
谢谢！！

Answer 1

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