Verified answer

1. A plane was made in USA. It was very expensive (Using: Ed-participle).

=> A plane was very expensive because they produced it in USA.

2. The question is very difficult. I can't answer it. (Using: adj+to-infinitive).

=> The question is too difficult for me to answer.

3. The ice is quite thick. We can walk on it. (Using: enough+to-infinitive).

=> The ice is thick enough for us to walk on.

4. Tung is very intelligent. He can solve this exercise. (using: so.....that).

=> Tung is so intelligent that he can solve this exercise.

5. It is very hot . Children can't go picnic.

=> It is too hot for children to go picnic.

6. Please turn down the radio for me, said my father.

=> My father asked me to turn down the radio.

7. I would like you to help me to put the chair away.

=> Do you mind putting the chair away?

8. Ba keeps forgetting his homework.

=> Ba is the student who always forgets his homework.

9. How long is it you used the car?

a) When did you start to use the car?

b) When did you start using the car?

10. It's five years since I last spoke to him.

=> I haven't spoken to him for five years.

:)