Grammar: Circle the correct answer. 5 How long ....... on this project? a have they been working b have they worked

• The correct answer is a have they been working. The question 'How long' asks about the duration of an activity that started in the past and may still be continuing. The present perfect continuous tense ('have they been working') is used to emphasize the duration of an action. 'Have they worked' (present perfect simple) can also be used, but the continuous form better emphasizes the ongoing nature of the work on the project.

Answer: a have they been working