BÀi 1: Chuyển các câu sang từ khẳng đình sang phủ định và nghi vấn.
1. This is Nam.
2.That is Hoa.
3.He is a teacher.
4.She is a dancer.
5.Hoa is a singer.
6. Hoa and Mai are pupils.
7.The flower is green.
8.The library is new.
9. I have a cat.
10.She has a cat.
11. They have a cat.
12.He has a cat.