1. This school was built many years ago.
2. It was such an interesting film that we have seen it three times.
3. Tuan is the tallest in my class.
4. She hasn't seen her grandfather for five months.
5. It took two hours to fly from Ha Noi to Ho Chi Minh.
6. I haven't heard this song since ten years ago.
7. The cake was so hard that I couldn't eat.
8. The cake was too hard for me to eat.
9. A letter is being written now.
10. How long has English been studied?