Produces the setdifference of two sequences by using the default equality comparer to compare values.
使用预设相等比较子来比较值，以便产生两个序列的差异。
2
While we're on the topic of little software features that can make a big difference, I want the ability to set an icon for a folder.
现在我们来谈论一个小的但能产生大的区别的软件功能项，我希望有给文件夹设定图标的能力。
3
Every attribute in the data set should be normalized, whereby each value is divided by the difference between the high value and the low value in the data set for that attribute.