18.1.
3. have been
4. has been
5. have lived
6. has worked
7. has had
8. have been learning
18.2.
2. How long have they been in Brazil?
3. How long have you known Margaret?
4. How long has Diana been learning Italian?
5. How long has my brother lived in Canada?
6. How long have I been a teacher?
7. How long has it been raining?
18.3.
2. She has lived in Wales all her life.
3. They have been on holiday since Sunday.
4. The sun has been shining all day.
5. She has been witing for 10 minutes.
6. He has had a beard since he was 20.
18.4.
2. know
3. have known
4. have you been
5. works
6. has been
7. have you lived
8. I've had
9. a) is
b) has been
