unproductive labor

例句：

1. 1. The company's new marketing strategy was unproductive in attracting customers.
   公司的新营销策略在吸引顾客方面是无效的。
2. 2. The research project was unproductive, failing to produce any significant results.
   这个研究项目是无效的，没有产生任何显著的结果。
3. 3.The farmer's efforts were unproductive, as the crops failed to grow well.
   农民的努力是无效的，因为作物生长得不好。