31.By the time we _____the airport, the plane_____

Nathalie suggested the problem worth paying attention _____ at the meeting. [ ]

“You can’t have this football back ____ you promise not to kick it at my cat again,” the old man said firmly[ ]

ass doors have taken the place of thewooden ones at the entrance,_____ in the natural light during the day

This Monday morning I was informed I _____ as one of three exchange students from our school.