Заполняем пропуски глаголами was или were, учитывая число подлежащего.
1. The third day was Wednesday. (The third day — единственное число).
2. The boys were in the swimming-pool. (The boys — множественное число).
3. Steve was the fastest swimmer! (Steve — единственное число).
4. On Thursday we were at the circus! (we — множественное число).
5. The bears were funny! (The bears — множественное число).
6. The fifth day was Friday. (The fifth day — единственное число).
7. In the morning we were in the zoo. (we — множественное число).
Ответ: was, were, was, were, were, was, were.