1)3.for
4.since
5.since
6.for
7.for
8.for/since
2)2. Two months ago
3. One day ago.
4. Five hours ago.
5. One week ago.
3)2.Jack has been here since Tuesday.
3.it's been raining for one hour.
4.I've known Sue since 2008.
5....have married for six months
6. ... has been studying medicine at university for three years.
7. ... has played the piano since he was seven years old.
4) I've known my best friend for many years.
I've been learning to play the piano for five years
I've had a cat for three years.
I've been studying in school since I was six years old.