从事工业或工程方面工作to be engaged in industrial or engineering work

投入工力to invest one's efforts or labour in(Britain); to invest one's efforts or labor in(US)

• 务工不多，收益不少。

  Moderate input produces considerable returns.

打工to work

• 数十万农民到镇上务工、经商。

  Many hundreds of thousands of farmers go into town to work or do business.

• 提高外来务工青年的整体素质。

  Improve the overall quality of young people coming to work from other areas.