这个城市的劳动力中有一半从事服务业。

Half of the city's ___labour force works in the service industry.

这家工厂的劳动力主要由年轻工人组成。

The ___labour force in this factory is mainly composed of young workers.

这个国家的劳动力主要由年轻人组成。

The ___labour force in this country is mainly composed of young people.