Dùng từ gợi ý viết lại câu sao cho nghĩa ko thay đổi 
1, Keeping the environment clean is very important
- It's ....................
2, They will show the time machine to the public when they finish it 
- The time machine ..................
3, He was delighted to receive his aun't letter 
- He was delighted that...............
4, Old car tires are recycled to make shoes and sandals
- Poeple ...................
5, I'm very sad that I wasn't accepted in that group
- I'm very sad not ..............
6, It's three years since I last spoke to her 
- I haven't ..............
7. Tam doesn't type á she used to 
- Tam used ..............
8, " please turm down the radio fir me " said my father