12. What is the formula for past perfect? A had + ing + V3 B have + V3 C had + V3 D had + V2 13. I ____ a sandwich, so I wasn't hungry. A have eaten B had eaten C have eat 14. We had already eaten when John _________________(come) home. A had come B came 15. When I ________________ (get) to thqe airport I discovered I had forgotten my passport. A got B had got 16. I went to the library, then I ______________(buy) some milk and went home. A bought B had bought 17. I opened my handbag to find that I ______________(forgot) my credit card. A had forgotten B forgot 18. When we ________________(arrive) at the station, the train had already left. A arrived B had arrived 19. Mona didn't __________ a story yesterday. A writed B write C wrote D wroted 20. She ____________ her car carefully yesterday. A drive B drave C drived D drove Ai jup e vs gấp ạ