按要求转换下列句式，每空一词。
1. His friend is from Canada. (改为同义句)
His friend ________ ________ Canada.
2. Is there a post office near here? (作否定回答)
________, there ________.
3. She plays ping-pong in the morning. (用now改写句子)
She ________ ________ ping-pong now.
4. She wants to be a doctor. (对划线部分提问)
________ ________ she want to be?
5. Mary is watching TV. (对划线部分提问)
________ is Mary ________?
