A separate new study looked at deaths worldwide in young people age ten to twenty-four.

VOA: special.2009.09.28

And that they are not these four separate subjects that you have to consider.

在这节课上，你不能孤立地考虑这四门学科。

与教授的面谈 - SpeakingMax英语口语达人

When you only have one classroom, but you have four different classes, you can only separate them by benches.

VOA: standard.2010.02.25

In recent days, four French soldiers have been killed in Afghanistan, in two separate accidents.

VOA: standard.2009.09.28