SN-1222 已核对来源，附原文与上下文。
嗯，做个备份没坏处，定期备份也是好习惯，不过不用，安装这个之前不需要备份。
Well, it can't hurt to do a backup and it's a good idea to backup regularly, but no, a backup is not required before installing this.
选择适合你的字号，之后阅读会继续使用。
