2 How long has Mary been teaching French?
She has been teaching French since 1990
3 How long have the robbers hiding in a farmhouse?
They have been hiding in a farmhouse for a week
4 How long has Peter been making model planes?
He has been making model planes since 1992
5 How long has Julie been playing the guitar?
She has been playing the guitar for four years
6 How long have the children been watching tv ?
They have been watching tv for two hours