1. They are going to school

2. Lan and Hoa are having breakfast

3. My father iss reading a book

4. The students are doing their HW

5. They are brushing their teeth

6. Mr and Mrs Smith are traveling to Ha Noi

7. My sister isn' t doing her homework. She is sleeping

8. His parents aren' t working in the factory. They are doing the gardening

Chỉ dùng nước và một dung dịch thuốc thử hãy phân biệt 5 chất bột màu trắng là BaCl2, MgSO4 BaSO4 Na2CO3 và BaCO3