Do not set sound to " autoplay " when someone visits your site . this can be very distracting 避免设置“自动播放”的音响，这样会分散用户的注意力。
2.
Use the autoplay parameter and attribute to set whether the movie starts playing automatically when the page loads ( true ) or if the user needs to hit the play button to start the movie ( false ) 利用自动播放参数、属性，决定网页下载完成后，电影自动播放，还是用户点击播放键之后播放。
