10/ It is monday since I last took a bath.
11 / She hasn't come back home for 4 years.
12. He has worked as a bank clerk for 3 months.
13. We have not flown to Singapore for 5 years.
14. I haven't had my hair cut since November.
15. We haven't called each other for 5 months.
16. We haven't met each other for a long time.
17. How long have you had it?
18. I have never had such a delicious meal.
