X/Rewrite the sentence without changing the meaning 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 aunt's letter. - He was delighted that 4. Old car tires are recycled to make shoes and sandals. - People 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 as fast as she used to. - Tam used 8. "Please turn down the radio for me", said my father. - My father asked 9. Lan will be fifteen next week. - It is Lan's 10. How long is it since you used the pen? - When