Complete the sentences,using the past perfect tence. When I arrived at the airport.I saw...

When I arrived at the airport.I saw that plane had taken off (plane/take off)
When Peter's mum asked him about his homework he said that he had done it (he/do)
When they got to Ann's place all the guests had left (all the guests/leave)
By the time I got home from school my grandma had cooked dinner (my grandma/cook dinner)
When the teacher came into the classroom pupils had learnt the results of the test (pupils /learn the results of the test)