用since和for填空

用since和for填空i’ve been here------two years i’ve been here------ yesterday i’ve been here-------i was a child i’ve been here-------two years agohe’s been in class --------4 o’clockhe’s been in class --------an hour agohe’s been in class --------4 hoursthey’ve lived in new york-------she left herethey’ve lived in new york-------1999they’ve lived in new york-------last month