vainly

The enemy vainly attempted destroying the bridge.

敌妄图破坏这座桥梁。

We tried vainly to discover what had happened.

我们设法想楚发生了什么事,但却徒劳。

The team captain vainly tried to rally his troops.

队长试图振作部队士气，但有成功。

He sought vainly for the answer.

他搜索枯肠, 但找不到答案。

The reactionary government tried vainly to take the steam out of the protest movement.

反动政府枉费心机地企图削弱这场抗议运动。