drive away at

• 拼命干，努力做(工作)，孜孜不倦地干：

  They were still driving away at the encyclopaedia.

  他们仍在孜孜不倦地编写那部百科全书。

  He sits at his desk for hours,driving away at his work.

  他一连几个小时坐在书桌旁，孜孜不倦地工作。