Вопрос:

5 The children ................. (study) since breakfast. 6 We ................. (think) of buying a house since last year. 7 (you/feel) ill for a long time? 8 Chris ................. (try) to fix the motorbike since Tuesday.

Ответ:

5. The children have been studying (study) since breakfast.
6. We have been thinking (think) of buying a house since last year.
7. Have you been feeling (you/feel) ill for a long time?
8. Chris has been trying (try) to fix the motorbike since Tuesday.