Kim`s been cleaning the house since 8 o`clock / for three hours.
She`s cleaned four rooms so far.
Bob`s been examining patients since 10 o`clock / for an hour.
He`s examined three patients so far.
John`s been delivering parcels since 7 o`clock / for four hours.
He`s delivered thirty parcels so far.
Helen`s been drawing pictures since 10 o`clock / for an hour.
She`s drawn four pictures so far.
