Despite our vain attempts to reach the supplier, the shipment remained stuck at customs.

儘管我們試圖聯絡供應商卻徒勞無功,貨物仍卡在海關。

The manager made a vain effort to save the merger during the final board meeting.

經理在最後一次董事會上力挽合併案,卻是白費力氣。

All our efforts to fix the booking system proved vain, so we called customer support.

我們修復訂位系統的所有努力都白費了,只好打電話給客服。