Ответ:
Negative
1. We haven't been cooking dinner since 11 o’clock.
2. My sister hasn't been working at this café for seven years.
3. They haven't been talking about English meals for half an hour already.
4. Helen hasn't been cooking Ukrainian beetroot soup since 12 o’clock.
Interrogative
1. Have we (you) been cooking dinner since 11 o’clock?
2. Has your sister been working at this café for seven years?
3. Have they been talking about English meals for half an hour already?
4. Has Helen been cooking Ukrainian beetroot soup since 12 o’clock?
Объяснение: