unproductive
adj. 非生产性的；徒劳的；不毛的；不生产的
例句
I've had a very unproductive day.
我这一天什么事都没干成。
《牛津词典》
Research workers are well aware that much of their time and effort is unproductive.
研究工作者们很清楚他们的大部分时间和努力都不会有成果。
《柯林斯英汉双解大词典》
If we weren't on our devices, we'd likely do something similarly unproductive.
如果我们不是在用自己的设备，我们很可能会做一些同样没有收益的事情。
