3.4 Present and Past speculations

SB p. 34:

Watch the video: L3_3.2_Present_and_past_speculation.mp4

Match the speakers' words to the explanations:

Complete the second sentence with must, might or can't.
1 It's possible that's our taxi. That       [might, must, can't] be our taxi.
2 I'm sure that's our plane. That       [might, must, can't] be our plane.
3 I'm sure those aren't our bags. Those       [might, must, can't] be our bags.
4 It's possible this is the hotel. This       [might, must, can't] be the hotel.
5 I'm sure this is our room. This       [might, must, can't] be our room.
6 We're sure that isn't our bill. That       [might, must, can't] be our bill.

Choose the correct forms.
At the aquarium ...
Nick: Look! An octopus.
Anne: Where? I can't see anything.
Nick: E r... well, the sign says there's an octopus, so it          [couldn't, must] be there somewhere.
Anne: I suppose it       [might, can't] be hiding under that rock.
Nick: Yeah, or it           [couldn't , could] be away on holiday...
Anne: On holiday? You       [can't, might] be serious. Honestly, I worry about you, Nick.
Nick: It says here that octopuses can change the colour of their skin and totally disappear. Cool. I'd love to be able to do that.
Anne: Nick, sometimes I think that would be a good idea.