17.Complete the fallowing sentences using since or for as required.
1. I haven''t seen you...
a)Christmas;
b)three days.
2.She hasn"t spoken to me...
a) an hour and a half;
b) January.
3. We"ve been here...
a) more than two years;
b) last week.
4. I haven"t had time to do it...
a) I was ill;
b) last Monday.
5. We haven"t bought any new magazines...
a) a week;
b) ages;
c) then.
6. I have become a vegetarian.I haven"t eaten any meat...
a) over a year;
b) I was a boy.
7. Nobody has written to me...
a) many weeks;
b) my bithday.
8. You"ve asked the same question every day...
a) the beginning of the year;
b) the last fortnight