1. How does the wind blow? （单数）2. Must I talk in English? No, you needn't.（一般用：Do I have to talk in English?问）3. You are not allowed to play near fires.4. We must leave the classroom quickly. We must not take anything with us. We must use a handkerchief to cover our mouths.5. What are your boots made of?6. There isn'...
