1. she has just gone out 2. she left 3. we have not yet solved ... 4.when did it all happen... 5. ... the wheather has changed... 6. ... you have made 7. a large black cloud has covered ... 8. ... all my papers have fallen... 9. when did you open ... - I opened ... 10, the sun has not risen ... 11. I saw 12. I have not read ... 13. ... trams have stopped ... 14. i low many times have you been ... 15. ... i have translated ... 16. we went ... the rain spoilt ... 17. ... it has stopped 18. the lecture has not yet begun ...