Complete the dialogue. Use modals of speculation or the future perfect where possible and the verbs in brackets.

A: What do you think about the origins of Stonehenge? Do you think the experts 1 (uncover) the mystery of the stones by the end of this decade?
B: I don’t think so. I mean, it 2 (be) easy as there are no records, so where do you start? People 3 (work) on the different theories for many decades to come, I think. I’m pretty sure 4 (build) by aliens.
A: Really? Why not? I mean, 5 (sound) a bit strange, but 5000 years ago people 6 (lift) stones up like that. They didn’t have the technology and that’s a fact! So, it 7 (be) some mysterious power or a supernatural explanation.
B: You 8 (be) crazy! We 9 (know) the answer, but that doesn’t mean to say we can just make up rubbish! You 10 (be) serious, surely!
A: No, of course not! But it was funny to watch your reaction! Ha ha!