Moodle里的Prevent和Prohibit有什么不同？

For Prohibit, no one will have permission even if you try to set 'allow' on override options.

otherwise if you set 'prevent' (higher context) it will always be defeated by 'allow' (lower context) and vice-versa.

摘自：http://moodle.org/mod/forum/discuss.php?d=63292

这简单的英文应该看得懂吧？

Couldn't find package libapache2-mod-security

Ubuntu Server

libapache2-mod-security was removed from Debian for licence issues. When a package is removed from Debian, Ubuntu usually removed it also.

摘自：http://ubuntuforums.org/showthread.php?t=513416

Root default password

刚玩linux的朋友可能会遇到一个问题，就是不知道root的密码。

其实不必这么麻烦，用以下程序就可以更换root的密码了。

sudo passwd root

如何更改Picasa Web Album Slideshow的背景颜色

How to change the background color of Picasa Web Album Slideshow.
如何更换Picasa Web Album Slideshow的背景颜色。

Change the code from RGB=0x000000& to RGB=0xFFFFFF& to make it become white.
把程式的 RGB=0x000000& 改成 RGB=0xFFFFFF& 就会变成白色了。