a closed mind的用法和样例：
- He has a closed mind.
- The manager has made her decision; she now has a closed mind on the subject and refuses to discuss it further.
- He believes in the literal truth of the whole Bible and has a closed mind on the subject. So we don't bother trying to argue with him.
- Nuclear physics is a closed book to me.
- Nuclear physics is a closed book to most of us.