The key answer of exercise 5

1

• Speaker 1 → It must have been amazing to be the first modern person ..., I think it must have been pretty hard to get there .., ... so they must have been really driven people ..., ... But, although they might have felt the same atmosphere when they were arriving, it couldn't have been quite as spectacular ..., ... but it must have had more of a mysterious air ...
• Speaker 2 → It can't have been easy because you have to realise ..., They must have been difficult to fly physically .., ... and that too couldn't have been easy.
• Speaker 3 → I think Yuri Gagarin must have had, I think. ..., never even had any concept of what it might look like from space ... ., just how amazing that must be ..., ... anything could have happened up there .., He must have felt alone.

2

• might
• could
• may

3

• can't be
• can't have had
• couldn't
• couldn't have taken

4

• must be
• must have been

5

• must be describes something in the present
• must have been describes a situation in the past