Rewrite the sentences using "-'s"

Rewrite the sentences using "-'s". Example: There was a party in the house of my friend. There was a party in my friend's house. 1. It was a present ofhis parents. 2. When do we celebrate the Day of Children? 3. How do you congratulate your grandmother on the Day of Woman? 4. Do we celebrate the Day of Teacher in September or October?