C CHUYÊN ĐỀ 7: ĐỘNG TỪ KHUYẾT THIẾU Complete with can/can't or could/couldn't. I This question's too difficult. I...can't 2 31 " ...answer it. you play the guitar three years ago? open the door because I didn't have the key. Mr Fox see us now? Or is he busy? 5 Have you seen my bag? I 6 ...