have sth. on one's mind

例句：

1. 1. I have a lot of work to do, so I can't focus on the game.
   我有很多工作要做，所以我不能专注于游戏。
2. 2. She has been thinking about her future for years.
   她多年来一直在思考她的未来。
3. 3. He had a lot of things on his mind, but he couldn't remember any of them.
   他有很多事情在心里，但他不记得任何一件。