根据所给提示，完成句型转换。每空一词，含缩略词。、
67. People there didn’t plant any trees last year. (同义句转换)
____________ trees ____________ planted by people there last year.
68. Why don’t you come to my birthday party? (同义句转换)
____________ ____________ come to my birthday party?
69. Mr Smith will be back in a week. （对句子划线部分提问）
____________ ____________ will Mr Smith be back?