Ответ:

were - потому что их двое; was - потому что там только Занкангер; was -  там только Джулия; were - их двое; was - Питер там только один; were -  двое действующих лиц

ответы на вопросы по порядку:

yes, they were.

no, he wasn't.  

yes, she was

yes, they were

no, he wasn't

yes, they were

Объяснение: