Match the sentences and say what you would do if: 1. you met your best friend after the summer holidays. 2. you went to the theatre with your mum. 3. you met your grandmother who lived in the country but had decided to visit you. 4. you got a birthday present. ---------------------------------------------- a) you would kiss her on both cheeks. b) you would say thank you. c) you would hold the door open for her. d) you would shake hands with him.

Here is the matching of the sentences based on standard social etiquette and the context provided:

1. If you met your best friend after the summer holidays, d) you would shake hands with him.
   • This is a formal or friendly way to greet a male peer after a long absence, assuming the "best friend" in this specific exercise is identified by the pronoun "him."
2. If you went to the theatre with your mum, c) you would hold the door open for her.
   • This reflects traditional polite behavior and manners when accompanying a lady or an elder to a public venue.
3. If you met your grandmother who lived in the country but had decided to visit you, a) you would kiss her on both cheeks.
   • This is a common affectionate greeting for close female relatives, especially after they have traveled a long distance to see you.
4. If you got a birthday present, b) you would say "thank you".
   • This is the universal polite response to receiving a gift or a kind gesture.

Next step: You can provide the original source or textbook name to see if there are additional etiquette rules or cultural variations to consider.