Ex 6. Viết lại câu sao cho nghĩa không đổi: 1. The last time we saw her was on Christmas day. We haven’t .................................................................................................. 2. I haven’t eaten this kind of food before.  This is........................................................................................................... 3. It started raining an hour ago. It has............................................................................................................. 4. We haven’t visited my grandfather for two months. The last time................................................................................................. 5. I have studied English for three years. I began.......................................................................................................... 6. My brother hasn’t seen his best friend for nearly five years. It’s ............................................................................................................... 7. When did you start learning English? How long...................................................................................................... 8. We started living here fifteen years ago. We have ....................................................................................................... 9. The last time she visited me was five years ago. She hasn’t..................................................................................................... 10. I last wrote to my uncle in July. I haven’t ...................................................................................................... 11. It’s long time since we became close friend. We have ....................................................................................................... 12. Minh began to collect stamps in 2000. Minh has......................................................................................................