大军

wǒ men shì xiān tóu bù duì dà jūn mǎ shàng jiù dào

我们是先头部队，大军马上就到。

We are the advance detachment. The main forces will be here soon.

jiě fàng dà jūn

解放大军

mighty liberation army

láo dòng dà jūn

劳动大军

large contingent of workers

shī yè dà jūn

失业大军

large numbers of unemployed

tā shì zhì yuàn zhě dà jūn de chéng yuán

他是志愿者大军的成员。

He is a member of the army of advisers/volunteers.