But experts say they are encouraged that the virus seems to be hitting hardest among people of middle age, sparing the more vulnerable groups - the elderly and children under the age of five.

VOA: standard.2009.04.28

This is one of the reasons why in the golden age of Arabic scholarship in the Middle Ages, there was so much dispute about the Poetics.

这就是为什么在,中世纪阿拉伯学术界的鼎盛时期，关于诗学有这么多争议。

耶鲁公开课 - 文学理论导论课程节选

I've given you the periods at the top of the chart: early Bronze Age; middle Bronze Age from about 2100 to 1550; we date the late Bronze age from about 1550 until 1200--the introduction of iron and the beginning of the Iron Age in 1200. Prior to that, the Bronze Age, which is divided into these three periods.

我在这个表格的顶端给你们列了一些时期：,早期青铜时代；中期青铜时代，从约公元前2100年到前1550年；,晚期青铜时代，从公元前1550年到前1200年，即铁器时代前页；,然后公元前1200年开始了铁器时代，在那以前，青铜时代分为那样三个时期。

耶鲁公开课 - 旧约导论课程节选

On average,those who were larger around the middle were more likely to have migraines than those of the same age with smaller waistlines.

VOA: special.2009.03.18