1. The bill must be paid at once
2. English is spoken in the world
3.  Your bicycle will be repaired  tommorow afternoon
4.  Miss Linda asked to the students not to  throw things away  
5. Many dangerous diseases can be cured by Penicillin
6. Is rice  exported to Britain by your country 
7. I was delighted to pass the exams 
8. It is very important to keep the environment clean
9.  He was delighted that his aunt sent he a leter 
10. People recycle old car tires to make shoes and sandals
11. i am very sad not to be accepted  in that group
12. It is difficult to understand this question
III
1. useful
2.what
3.of
4. many
5.knowledge
6. friendship 
Iv 
1. If i were you,i would learn harder
2. . My brother wishes that  he could speak english fluent as native speaker 
3. I asked  whether he studied at a university in America the