regretting

vt. 后悔, 悔恨（regret的现在分词形式）

regret /ri'gret/

n. 遗憾, 后悔, 悔恨, 抱歉, 歉意
vt. 为...感到遗憾, 后悔, 惋惜, 懊悔, 抱歉
vi. 感到抱歉

Devalue your time wisely; otherwise, you'll find yourself regretting lost opportunities.

明智地利用你的时间；否则，你会发现自己后悔失去的机会。

The anguished look on his face suggested that he was regretting his decision.

他脸上那饱含痛苦的表情说明他在为自己的决定感到后悔。