Respuesta:
1. They normally **have** lunch at two. (have)
2. Are **you working** in Paris this week? (you work)
3. You **buy** new clothes every Saturday! (buy)
4. I **played** football at school but now I **prefer** swimming. (prefer)
5. I **have** no idea what the book is about. Can you tell me what it's about? (have)
6. John **is having** a difficult time at the university this year. (have)
7. My father **knows** everything about cars, but knows nothing about bicycles. (know)
8. The moon **goes** round the earth. (go)
9. **Are you looking** very strangely at those men at the door? - They **are looking** at us. (you see, look)
Espero que estas correcciones te ayuden a completar las oraciones de forma correcta.