p. 112, ex. 5
1. Where has Mary been running for two hours? She has been running at the stadium for 2 hours.
2. How long has Ann been training in the gym? Ann has been training in the gym for three hours.
3. What game has Steve been playing for 2 hours? He has been playing basketball.
4. Who has been training Sue for five years? Mrs. Fletcher has been training Sue for five years.