regretfully
adv. 懊悔地，遗憾地；抱歉地
例句
He shook his head regretfully.
他遗憾地摇了摇头。
《柯林斯英汉双解大词典》
Regretfully, some jobs will be lost.
遗憾的是有些人将会失去工作。
《牛津词典》
'I'm afraid not,' he said regretfully.
他遗憾地说：“恐怕不行。”
