Keeping the enviroment clean is very important

1. keeping the enviroment 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 aunt's letter
- he was delighted that ...............
4. old car tires are recycled to make shoes and sandals
- people .................
5. I'm very sad thatI wasn't accepted in that group
- I'm very sad not ...............
6. It' three years since I last spoke to her
- I haven't ...........
7. Tam doesn't type as fast as she used to
- Tam used ...............
8. " please turn down the radio for me " , said my father
- my father saked .............