EX4: Choose the best answer ( giải nhanh hộ em vs ạ, ghi từ đúng để điền vào chỗ trống thôi ạ) 51. We’ve been here ............last week. A. since B. for C. by D. from 52. They haven’t seen each other ...........a long time. A. since B. for C. with D. about 53. My mother..........in this hospital for 9 years. A. have worked B. worked C. has worked D. works 54. ...........you had breakfast since 6.00 a. m ? A. Do B. Does C. Have D. Has 55. I have.........her for some years. A. know B. known C. knew D. knowing 56............ have you lived here? A. When B. How long C. What time D. What 57. I ...................................my book . I can’t find it anywhere. A. lost B.have lost C.has lost D. lose 58. For a long time, the ¸Ao dai................the subject of poems,novels,and songs. A. were B.was C.have been D.has been 59. I don’t know Minh.I............................met him. A. have never B.never have C.haven’t never D.ever haven’t 60. a teacher.......................he was 20 years old. A. for B.about C.at D.since