ex1

1.was

2.were

3.were

4.were

5.was

6.were

ex2

1.wasn't

2.wasn't

3.wasn't

4.wasn't

5.weren't

ex3

1. were you at the cinema?-yes i were

2.were they at go-kart-track?-no they weren't

3.was Robin at the beach yesterday?-no he wasn't

4.were Olive and Megan at the restaurant?-yes they were

5.were you in the school yesterday?-no i wasn't это правильно