Write the following sentences after the model, paving attention to the subject of the sentence

Example:
The man save her the book.
=> It was the man who gave her the book.
1. The boy visited his uncle last month.
2. My mother bought me a present on my birthday.
3. Huong and Sandra sang together at the party.
4. Nam’s father got angry with him.
5. The boys played football all day long.
6. The girl received a letter from her friend yesterday.
7. His presence at the meeting frightened the children.