2. They didn't go with their parents. They went with their grandparents.
3. They didn't wear school uniform. They wore casual clothes.
4. They didn't see the exhibition about the ancient Greeks. They saw the exhibition about the ancient Egyptians.
5. Tom didn't take his MP3 player with him. He took a digital camera with him.
6. Lucy didn't buy a book from the gift shop. She bought some pencils.