The national security challenge comes at a difficult time for Mr.Obama, who later this month will mark his first year in office.

VOA: standard.2010.01.06

One way to mark time is to imagine it carries a clock as it moves, and put markers every second.

标记时间的一种方法是,想像它带着时钟运动,并且每秒做一次标记

耶鲁公开课 - 基础物理课程节选

I am on the internet, probably every time I mark,

我上网的时候，几乎每次都会标记清楚，

对于抄袭的想法 - SpeakingMax英语口语达人

If the Nairobi summit is successful, the Copenhagen talks will mark the first time Africa will be entering the global climate change negotiations under a common position.

VOA: standard.2009.10.13

And by this time Mark Antony had palled up with Cleopatra, Queen of Egypt, and Octavian beat both of them, and he became the sole ruler of the empire in 27 BCE.

安东尼与埃及女王克利奥帕特拉先后自杀，屋大维击败了他们两人，于公元前27年成为了帝国的独裁者。

耶鲁公开课 - 新约课程节选

Now it has hit an all time low, dipping below the 60,000 mark.

VOA: standard.2009.10.27

Then there are certain holy days: and they are separated and demarcated from common time by special rules that mark them as different.

然后是一些神圣日：,和普通的时间,被一些特殊的判定它们不同的规则所区分开。

耶鲁公开课 - 旧约导论课程节选

Long-time Murtha aide and Democrat Mark Critz won that seat Tuesday in a conservative district that voted for Republican John McCain over Democrat Barack Obama in the 2008 presidential election.

VOA: standard.2010.05.19