"And that's the duty of everyone who believes in justice and in deterring the gravest and most serious types of crimes that the United Nations was partially set up to prevent after the Second World War, and continues to fail to prevent."

VOA: standard.2009.09.07

And it turned out that another, not quite as deadly, but still very serious disease called syphilis was also common in this part of the world at that time.

现在已知另外一种疾病,它并不完全致命但也很严重,它叫梅毒,在那时的一些地方也很常见

耶鲁公开课 - 生物医学工程探索课程节选

Unemployment is a serious issue in many parts of the world.

在世界很多地方，失业率都是一个严重的问题。

就业很难 - SpeakingMax英语口语达人