1. Where are the jeans? I'm sure I looked everywhere.
2. The centre was crowded with people.
3. Were the children at home at eight yesterday?
4. Look at these nice glasses! My last pair are not very comfortable.
5. The sportsmen were proud of taking part in the Olympic Games.
В данной задаче глагол «to be» в форме «were» встречается чаще, чем в форме «was».
Ответ: were