Переведите на русский язык.
1. You must work hard at your English. 2. You must learn the words. 3. Must we learn the poem today? 4. It must be very difficult to learn Chinese. 5. You must not talk at the lessons. 6. Everybody must come to school in time. 7. Don't ring him up: he must be very busy. 8. You must not make notes in the books. 9. I must help my mother today.