4. ¹)Has gone
²)Has been
³)have been
⁴)I haven't
⁵)have gone
5.
²)had
³)already seen
⁴)will visit
⁵)are meeting
⁶)works
⁷)lived
⁸)we did not explore
⁹)knows
¹⁰)have you arrived
¹¹)are you still travelling
