срочно!!!!!!Write the sentences in the Past Perfect Continuous Tense.

1) Ann's sister __________________ (to prepare) for two weeks before that exam.

2) Alex and Jo __________________ (to take) pictures in the airport for 15 minutes before Jo left.

3) The Browns __________________ (to discuss) the family budget for more than an hour before they reached the agreement.

4) Sarah __________________ (to wait) for half an hour before she saw her daughter getting off the bus.

5) Driving to work was difficult as it __________________ (to snow) all weekend.

6) Sally __________________ (to study) Biology since she entered college.

7) When Julie's husband returned home she __________________ (to make) dinner for half an hour.