1.The hardest work was assigned to the strongest laborers.

1.最繁的作分配给最强壮的劳。

2.Laborers were trained to handle 50-ton compactors and giant cranes.

2.接受操作五十吨压土机和巨型起机的训练。

3.A laborer takes a rest on a cinder dumpsite in Changzhi, China.

3.在中国长治，一名在圾场酣睡。

4.Subject of labor is practice object subsystem, laborer is subsystem of practice main body, labor tool is practice neutretto system, productivity is the integral function that carries out a system.

4.劳动对象是实践客体子系统,劳动者是实践主体子系统,劳动具是实践中介子系统,生产力是实践系统的整体功能。