1. Tet / most / important / festival / Vietnam. A. Tet is the most important festivals Vietnam. B. Tet is most important festival in Vietnam. C. Tet is the most important festival Vietnam. D. Tet is the most important festival in Vietnam. 2. They/ play/ tennis/ 10.30 yesterday morning. A. They were play tennis at 10.30 yesterday morning. B. They was play tennis at 10.30 yesterday morning. C. They were playing tennis at 10.30 yesterday morning. D. They was playing tennis at 10.30 yesterday morning. 3. We / know / each other / since / we / be / ten years old. A. We knew each other since we has been ten years old. B. We have known each other since we were ten years old. C. We knew each other since we were ten years old. D. We have known each other since we has been ten years old. 4. You/ have /take / off / hat / when / go inside / main worship area. A. You have to take off your hat when you go inside the main worship area. B. You has to take off your hat when you go inside the main worship area. C. You have to take off your hat when you went inside the main worship area. D. You had to take off your hat when you went inside the main worship area. 5. A lion / run / fast / than / horse. A. A lion runs fastly than a horse. B. A lion is run faster than a horse. C. A lion runs fastlier than a horse. D. A lion runs faster than a horse.