Past Perfect and Simple Past

2. When I had arrivedarrived (arrive) at the airport, my flight already departedhad already departed (already, depart).

3. She finishedhad finished (finish) her presentation before it had startedstarted (start) raining.

4. They had never visitednever visited (never visit) that museum before they had hadhad a school trip.

5. By the time the concert startedhad started, I already foundhad already found (already, find) my seat in the front row.