1.played piano for 4 years
2.cooked for the party for 4 years
3.has worked as a secretary for 2 years
4.has read newspaper for 2 years
5.has studied E for 1 year
6.fighted against AIDS in1980
7.living in london 20 years ago
8.working for this electronics firm in 1990
9.fighting for their rights in the middle of the 20th of century
10.learning to drive 2 weeks ago
11.did you study E?
12.have you begun to do research on lung cancer?