Choose the correct option that completes the sentences using...
Choose the correct option that completes the sentences using either "for" or "since".
1 - She has lived in this city _____ 2010.
2 - They have been friends _____ many years.
3 - I haven't seen him _____ last week.
4 - We have worked together _____ five months.
5 - He has been studying _____ I arrived here.