Đổi các câu sau sang dạng số nhiều
1. This house is old
2. That box is small
3. Is Lan's sister beautiful ?
4. He is our teacher
5. Who's he ?
6. Is this a ruler or an eraser ?
7. What is this ?
8. Your chair is old
9. There is a garden behind my house
10. No, it isn't. It's new.