Use the necessary modal verb in the correct form. 1. Peter ___ return the book to the library. We all want to read it. 2. Why ___ not you understand it? It is so easy. 3. When you work, you ___ agree with your boss. 4. ___ you pronounce this sound? 5. You ___ not buy any meat: we have everything for dinner. 6. I ___ not go out today: it is too cold. 7. You ___ not enter this room, it is forbidden! 8. We ___ not carry the bookcase upstairs ourselves: the workers will come and do it. 9. The clouds are dark. You ___ take an umbrella.