Fill in: Hmm ... I don't know., I love extreme sports!, What do you think?, What happened?, Let me think about it., It was fantastic!, I’m not sure that 's a good idea., I prefer safer sports.

a)
1 What happened?
2 It was fantastic!
3 I prefer safer sports.
4 I love extreme sports!

b)
1 What do you think?
2 I'm not sure that's a good idea.
3 Hmm... I don't know.
4 Let me think about it.