passe as frases para a forma negativa e forma interrogativa.
A)Those were my brothers
F.N ______________________
F.I _______________________
B)That was a beautiful lion
F.N ______________________
F.I _______________________
C)These were our dogs
F.N ______________________
F.I _______________________

Soluções para a tarefa
Resposta:
1° -Those weren't my brothers
Were those my brothers?
2° That wasn't a beautiful lion
Was that a beautiful lion?
3° These weren't our dogs
Were these our dogs?
Resposta:
A) Negativa: Those weren't my brothers.
Interrogativa: Were those my brothers?
B) Negativa: That wasn't a beautiful lion.
Interrogativa: Was that a beautiful lion?
C) Negativa: These weren't our dogs.
Interrogativa: Were these our dogs?
Explicação:
Para passar "were" para negativo, basta você acrescentar o "not" logo após "were" ou contraílos em "weren't".
Para passar para uma frase interrogativa, basta você passar o verbo to be (no caso) para trás do sujeito (no caso those, that e these).
Você pode também pode fazer uma frase interrogativa negativa como esta:
"Weren't those my brothers?"
Ambas as respostas estariam corretas.
Espero ter lhe ajudado ;)