1. important to keep the environment clean

2. will be shown to the public when it is finished

3. he received his aunt's letter

4. recycle old car tyres to make shoes and sandals

5. to be accepted in that group

6. spoken to her for 3 years

7. to type faster than she does now

8. me to turn down the radio for him

9. fifteenth birthday next week

10. did you last use the pen

1.It's important to keep the environment clean

2.the time machine will be shown to the public when it is finished

3.He was delighted that his aunt sent him a letter

4.People recycle old car tires to make shoes and sandals

5.I'm very sad not to be accepted in that group

6.I haven't spoken to her for three years

7.Tam used to type faster than she does now

8.My father asked me to turn down the radio for him

9.It is Lan's fifteenth birthday  next week

10.When did you use a pen?