The bright nucleus is home to an older population of stars, which grow ever more densely packed toward the centre.
星云明亮的核心是老一代星体所在，越靠近中心密度越大。
2
Work by the Glasgow Centre for Population Health has confirmed the link between social factors and the rate at which people age.
格拉斯哥居民健康中心已经证实了社会因素与人们老化速度的关系。
3
To accommodate the rapid influx of population, city council plans to encourage high density housing in its town centre area which lies between Blundell and Bridgeport on both sides of No. 3 Road.