一些技术公司，如亚马逊，苹果可以经常设定零售价。
Technology firms such as Amazon and Apple can often set retail prices.
除非你有办法接收通知(如亚马逊的背景工作)，投票几乎是你唯一能做的。
Unless you have some way to receive notifications (like Amazon does for its background jobs), polling is pretty much the only thing you can do.
如果你是从自己的CD上导出或从正版源下载，如亚马逊，那你该把此音乐文件夹安全排除。
If you've ripped your own CDs or downloaded from somewhere legitimate like Amazon, then you can safely exclude your music folder.
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