Réponse:
a. 1. I'm so hungry. It's already one o'clock and I am used to having lunch at twelve
2. She had one glass and then said she didn't want anymore because she is not used to drinking wine
3. Paul is very homesick because he is not used to being away from home.
4. "No one can hear what he's saying." "That's because he isn't used to speaking in public"
5. She didn't want to go camping because she is used to sleeping in a comfortable bed