25 He hasn't written to me for 3 months
26 The last time he wrote to me was 3 months ago
27 It's 3 months since he last wrote to me
28 Hoa hasn't met her old friends since they left school
29 I haven't read "War and Peace" Since 2005
30 It's 2 years since we last visited HN
31 I haven't seen him since I was a student