我们很遗憾地通知您，您的请求已被拒绝。

We ___regret to inform you that your request has been denied.

她遗憾地表示她无法参加会议。

She ___regrets that she cannot attend the meeting.

我很遗憾地告诉您，活动已取消。

I ___regret to tell you that the event has been canceled.