Ответ:

3. When we moved to our street, a new school would be finished soon.

a) is being built

b) was being built

there. We understood it

Событие (переезд) произошло в прошлом, строительство происходило и продолжалось какое-то время.

c) has been built

d) had been built

Ответ: b) was being built