a mental patient的用法和样例：
- Sorry, comrade!He is a mental patient!
- In a mand house, a mental patient was writing letter.
- One night the woman was reading her newspaper just before going to sleep.She shivered and pulled the comforter up around her as she read that a mental patient had wandered off from a nearby hospital.
- He has a mental block about maths.
- He was certified and sent to a mental hospital.