Chọn thì thích hợp nhất để hoàn thành các câu sau: 47. Jack ___________ the door. A. has just opened B. opening C. open D. will have opened 48. By the age of 25, he ________________two famous novels. A. had written B. has written C. writes D. wrote 49. After I ____________lunch, I looked for my bag. A. have had B. had had C. had D. was having 50. The man got out of the car, ______round to the back and opened the door. A. walk B. walking C. walks D. walked 51. Before you asked, the letter ________________. A. has been written B. was written C. had been written D. had written 52. I ______________in Hanoi before I moved to HCM City. A. had been living B. had lived C. have lived D. have been living