Read and write.按照要求改写句子。
（1）My mother is a doctor. (就划线部分提问)
_______________________________________________?
（2）He has bread for breakfast.(改为一般疑问句)
_______________________________________________?
（3）They visited Beijing last year. (改为否定句)
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（4）Those are knives.(改为单数句)
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（5）Are you a student or a teacher? (按照实际情况回答)
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