Переведите словосочетания на английский язык и закончите предложение: My friend has worked on the problem of consumers’

My friend has worked on the problem of consumers’ behaviour in the market ... 1) since 2001; 2) for two years/ during two years; 3) since he left/ finished the university; 4) for a long time; 5) for a week; 6) since summer; 7) since last month; 8) since he became the manager of the company; 9) for the whole working day.