15. We were playing the guitar while our father ___________ in his room. A. works B. is working C. was working D. has been working 16. We met our teacher while we ________ in the park. A. were running B. was running C. running D. ran 17. He ____________less than an hour when he ran out of petrol. A. had driven B. had driving C. had drived D. drove 18. My mother_____________ in this hospital for 9 years. A. have worked B. worked C. has worked D. works 19. Who ________ with at the party last night? A. dancing B. did she dance C. she danced D. was she dancing 20. He has used his motorcycle _____________. A. 5 years ago B. since 5 years C. for 5 years ago D. for 5 years 21. Columbus_____________ America more than 400 years ago. A. discovered B. has discovered C. had discovered D. he has gone 22. He fell down when he ____________ towards the church. A. run B. runs C. was running D. had run 23. We were studying English when it ___________ heavily. A. rains B. rained C. was raining D. will rain 24. I ___________to New York three times this year. A. have been B. was C. were D. had been 25. John ___________ for three tests this month. A. sat B. have sat C. has sat D. is sitting 26. After he graduates, he ___________ a job. A. has found B. finds C. found D. will find 27. The teacher ________ out when I arrived in the classroom. A. goes B. have gone C. has gone D. had gone 28. I ______ my document before the power went out in the computer lab. A. had save B. have saved C. had saved D. saved CÁC BẠN GIẢI VÀ GIẢI THÍCH CHI TIẾT GIÚP MÌNH VS Ạ