The conference occurred this week as U.S.law enforcement agencies are engaged in a nationwide crackdown on human trafficking.

VOA: standard.2009.11.13

This idea that humans have evolved, that physical changes have occurred in humans as a consequence of their food environment, has led us to where we are now.

探讨人与食物的关系,探讨人类机体,由于食物环境而产生的变化,是我们今天坐在这里的原因

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

So they kept track of country-by-country, when cases of smallpox occurred, and as it was eliminated from regions of the country, they then certified those regions to be smallpox free.

它跟踪调查了一个又一个国家,记录天花在这个国家中何时发生,又是何时清除的,并确证这个区域已经没有天花

耶鲁公开课 - 生物医学工程探索课程节选

The latest attack occurred Friday as Parliament was in session for the aid package debate.

VOA: standard.2009.10.16

This allegedly occurred when he served as mayor of Jerusalem and a Cabinet minister, but the allegations only surfaced after he became prime minister in 2006.

VOA: standard.2009.09.25

And with respect to the announcement that occurred when the vice president was there, we've expressed our dismay and disappointment and we have, as I said earlier engaged in consultations with our partners in the peace effort - the Israelis and the Palestinians - about the way forward."

VOA: standard.2010.03.16