He has just come back form a southern city 为什么用a

He has just come back form a southern city 为什么用a he has just come back i just come back form he has just come out a book为什么是错的 he--in there days.a.has come back b.came back c.will come ba my father--------just-------(come)back form work. My father __ ___ ___Shanghai.He has already come back .A.has ( ) Uncle Jack has Los Angeles.He will come back a week.A.go He has just bought a new house in the city.（改为被动） A:Where___you come form? I hear that John has come back to china,_____? A.isn't he B. Would you please tell me__?A.when he has come back B.where h