вставьте модальные глаголы саn , may , must, need:1. Shall i

Воткните модальные глаголы саn , may , must, need:
1. Shall i write a letter to him?-no,you ... not,it's not necessary. 2. ... i offer you something to drink? 3. Everything is clear and you ... not go into detail now. 4. He ... not drink alcohol when he drives. 5. Don't worry! i ... change a light bulb. 6. By the end of the week i ... have finished writing my book. 7. She ... not call the doctor again unless she feels worse. 8. Peter ... return the book to the library. We all want to read it. 9. Why ... not you understand it? It is so easy. 10. ... we do the exercise at once?- yes, you ... do it right now.