1. I run in the forest. 2. It runs in the park. 3. Martin rides a bike. 4. They live in Africa. 5. She dances well. 6. They run in the park. 7. I skate in the park. 8. I take five books. 9. The pupil sings songs. 10. The pupils sing songs. 11. The cat likes milk. 12. The cats like milk. 13. My friend helps me. 14. My friends help me. 15. I help my friend.