1. My mom keeps telling me how guilty she feels for not having taken good care of me when I was little. The truth is she could not have done better.2. A motorcyclist hit an old woman. She is in the emergency room now. He is grief-stricken over causing her the serious injury.
 guilty grief-stricken over something內疚用 guilty 或 grief-stricken 都很好用
It gives the ilusion that you've computed the entire answer immediately.