Чтобы правильно заполнить пропуски, нужно понять, о чем идет речь: о чем-то единственном или о чем-то во множественном числе. Также нужно учитывать, что there was/wasn't используется с существительными в единственном числе, а there were/weren't — во множественном.
When I was at primary school there weren't a lot of exams and there were a lot of students in my class – I think there were only nine or ten of us. In my classroom there was an internet connection or an electronic board, but it was beautiful. There were pictures and stories on the walls and there was a storytelling hour every day. There weren't any computers or laptops in our class, but we loved writing on the little green board!
Ответ: weren't, there were, there were, there was, There were, there was, weren't.