Think Back! Look at the underlined verb forms in Exercise 1

obligation/necessity обязательство / необходимость: must, have to, need, be required to, be obliged to
duty and advice долг и совет: ought to, oughtnt to, should, shouldnt, be supposed to
no obligation / necessity никаких обязанностей / необходимости: dont have to, neednt, not required to, not obliged to
ability or lack of ability умение или неимение способности: can, cant, could, couldnt, be able to, manage to, succeed in
prohibition запрет: mustnt, cant, couldnt, not allowed to, be forbidden
permission разрешение: can, could, be allowed, be permitted to
possibility/probability возможность: can, could, might, likely to, be bound to