A professional writer?的用法和样例：
- It struck me as the production of a professional writer.
- As I am not a professional writer, to keep living is my first requirement. Just as the proverb expressed: "Bread is a necessity before be in love".
- As I became a professional writer, doing books and plays and films, it became clearer and clearer to me how fortunate I had been.
- He plays the flute like a professional.