1. She looked at him sadly, knowing that they could never be together.
她悲伤地看着他，知道他们永远无法在一起。
2. Sadly, the concert was canceled due to the heavy rain.
遗憾的是，因为大雨，音乐会被取消了。
3. He sadly shook his head, realizing that he had made a terrible mistake.
他遗憾地摇了摇头，意识到自己犯了一个可怕的错误。