past half 过去的一半；

例句：

Spatial and temporal precipitation variation on the Loess Plateau in the past half century

半个世纪以来黄土高原降水的时空变化

相关介绍

Great changes in public housing were evidenced during the past half century in Shanghai.

通过总结全文，可以看出上海公有住房制度在短短半个多世纪中发生的巨大变化。

Their emergence reflects the various aspects of the past half century the reality of Chinese society.

他们的出现反映了半个世纪以来中国社会各方面的现实。