How long has your mother been cooking dinner? — My mother has been cooking dinner for two hours.How long have you been boiling pork and beef? — I have been boiling pork and beef for three hours.How long haven't you been to this restaurant? — I haven't been to this restaurant for five years.How long haven't you been drinking orange juice? — I haven't been drinking orange juice for a week.How long haven't you been eating pork chops and roast beef? — I haven't been eating pork chops and roast beef for a month.How long haven't you been eating strawberry ice-cream? — I haven't been eating strawberry ice-cream for a week.How long have you been reading that cookbook in English? — I have been reading that cookbook in English since June.How long have you been cooking fish and chips? — I have been cooking fish and chips since 2 o'clock.