Present Perfect Continuous

Helen ______________ the dishes for fifteen minutes.

My classmates ________________ a dictation since the beginning of the lesson.

I ____________________ for information on the subject since last Friday.

We ________________________ in the garden for three hours.

It _________________ since afternoon.

Kim _________________ her things for so long.

__________ the baby ____________ for half an hour?

__________ they _____________________ for the test for two days?

They have been skiing _________________ lunch.

She has been singing _____________ two hours.

She has been living in London _______________ last summer.

She has been preparing for her exams ________________ the last two months.