Question

1)a)just have read b)'ve just read
2)a)nut exist b)didn't exist
3)a)uses travel b)used to travel
4)a)are travelling b)travel
5)A)discover b)are discovering
6)a)have b)are having
7)A)are completing b)completed
8)a)travel b)to travel

Answer 1

1b
2 b
3 b
4 b
5a
6 a
7 b
8 a