1. That tree is in front of my house.

2. There is a book on the desk.

3. There is a woman near the house.

4. I’m a student.

5. She is a doctor.

6. There is a picture on the wall.

7. Is there a baby in the room？

8. This is a cat.

9. That is a dog.

10. The boy has a ball.

11. She has a rabbit.

12. The baby is sleeping.

13. I have a car.

14. He is an American boy.

15. It is a car.

16. This is an eraser.

17. That is a backpack.

18. I am an English teacher.

19. It’s a new shirt.

20. He is a boy.

21. She is a singer.

22. What is this？

23. That is Jack’s book.

24. I am a student.

25. It is my pen.

26. He is a policeman.

27. There is a goat in the garden.

28. Is there a leaf in the box？

29. She is going to catch a butterfly.

30. My sister has a box.

这些题目涵盖了各种常见的单数句子结构，并提供了相应的复数形式，有助于学生掌握名词、代词和谓语动词的复数变化规则。