Выполните грамматические упражнения на Present Perfect Continuous
(раскройте скобки)
1 The grandfather (take) this medicine for months. 2 How long the examiners ( ask) students? 3 This
system (not work) for many years. 4 They (wait) for a long time? 5 Fres and Kelly (stay) in the country
for the whole summer.

The grandfather has been taking this medicine for months. How long the examiners have been asking students? This system hasn't been working for many years.Have they been waiting for a long time?Fres and Kelly have been staying in the country for the whole summer.