她的工作意味着她长时间不在家。

Her work means that she spends long ___periods away from home.

今年上半年的失业率比去年同期低2%。

Unemployment in the first half of the year was 2% lower than in the same ___period last year.

这项研究将在六个月内进行。

The study will be carried out over a six-month ___period.