they came here for a year这句哪错了?

they came here for a year这句哪错了? They came here for ayear哪里错了 Mr.Brown worked in a bank for a year before he came here.这个句 he came here in 1980.he has been a teacher for cver ten year He had studied English for a year before he came here 其中的bef i ___(记得)they once came here for dinner. you came here at a bad time of year they came here an hour ago 改为同义句 they ___ ___ here for an ho 21.A month ____ since they came to here. He came here a year _______,and I have been here _______ two they have been married for a year. Did they build a house here a year ago?