He banged away at the speech for days.

他用了许多天写完了演讲稿。

She banged away at the piano.

她在随意地弹钢琴。

He's been banging away at that project all week.

她为了这个项目辛苦工作了一个星期。

Grant was in hot pursuit, banging away at the Confederates from both sides and the rear, while Sheridan's cavalry was heading them off in front, tearing up railway lines and capturing supply trains.

格兰特紧追不舍，从两侧和后方猛烈攻击同盟军，而谢里登的骑兵则在前方阻止他们，撕毁铁路线并夺取补给列车。