Ответы на вопросы:
- Is he going to climb a mountain? - Yes, he is.
- Are you going to visit a theme park? - No, I'm not.
- Are your parents going to take a bus tour? - Yes, they are.
- Is Emily going to go snorkeling? - No, she isn't.
Дополнительные варианты: Yes, he isn't.; No, she is.